Because they weren't even remotely in the same position, no "more or less" about it.

There are dozens and dozens of differences but let's just go straight for the big one: Britain, on June 22 1940 had a large, powerful navy and open lines of supply with its vast Empire and Commonwealth allies. Nazi Germany did not have a surface fleet capable of matching it on the high seas and its U-Boat fleet was not in a position to blockade the Home Islands. The coming war in the air would falter because Nazi Germany neither had the fighters nor the strategic bombing forces capable of defeating the Royal Air Force.

Imperial Japan by late 1944 had lost its last major surface fleet and was increasingly cut off from its overseas empire by vastly larger and better equipped American surface and submarine fleets. Within months the US would commence bombardment of the Japanese Home Islands with long-range strategic bombers each capable of carrying more than four times the bomb load of the heaviest German bomber. Unlike Britain, Japan lacked an air force capable of meeting that threat - its planes by that point were largely grounded due to the shortage of fuel produced by aforesaid American naval blockade.

The situations of Britain in 1940 and Japan in 1944 were vastly different from each other.

Although the swift Fall of France did demoralize the British in 1940, the British themselves were still in a very good position. The Royal Navy was superior to the German Kriegsmarine, which allowed the British to establish naval dominance, protect supply lines, and most importantly thwart any naval invasion attempt of the British Isles. Britain also had a vast colonial empire backing them up with both supplies and manpower.

Japan's situation in 1944 on the other hand was very desperate. Japan's supply situation was critical by that point in the war. One of the main reasons Japan became so aggressive in the first place was because their country lacked supplies, and now when they went to war, they were severely strained for supplies and raw materials. By 1944 Japan had taken so many losses they ability to recover, whereas a 1940 Britain was still fresh to fight. The US army was rapidly approaching the Japanese homeland, where Britain could have never been invaded by Germany successfully.

As covered by the other replies, the situations aren't really similar. Though Germany dominates the continent in 1940 the Royal Navy is still formidable, and as the Battle of Britain demonstrated the Luftwaffe were unable to secure air superiority for a possible invasion, or bring about victory through strategic bombing. Focusing on plans for the invasion of the Soviet Union, Germany had neither the military capability nor political will for a successful invasion of Great Britain (see, e.g., Peter Fleming, Operation Sealion).

The USA was of course neutral, but supporting the UK via the "cash-and-carry" clause of the 1937 Neutrality Act, expanded in 1939:

"Since vital raw materials such as oil were not considered “implements of war,” the “cash-and-carry” clause would be quite valuable to whatever nation could make use of it. Roosevelt had engineered its inclusion as a deliberate way to assist Great Britain and France in any war against the Axis Powers, since he realized that they were the only countries that had both the hard currency and ships to make use of “cash-and-carry.”"

(Office of the Historian, US Department of State: https://history.state.gov/milestones/1921-1936/neutrality-acts )

Churchill was campaigning for greater support from the US, forthcoming with initially e.g. Lend-Lease, and despite the Molotov-Ribbentrop pact believed that Germany and the Soviet Union would eventually go to war:

"We none the less pursued a patient policy of trying to re-establish relations of a confidential character with Russia, trusting to the march of events and to their fundamental antagonisms to Germany."

(Winston Churchill, The Second World War)

So the UK still had a powerful defensive navy and air force, the Empire/Commonwealth, supplies from the US and the possibility of further support from the United States and/or Soviet Union. Without straying too far into hypotheticals a more isolationist US or continuation of the Molotov-Ribbentrop pact could have led to a bleaker situation, but things were by no means hopeless.

By late 1944 the Imperial Japanese Navy has been decimated, notably suffering heavy losses in the Battle of the Philippine Sea (nicknamed 'The Great Marianas Turkey Shoot' by American aviators) and the Battle of Leyte Gulf. USAAF B-29s could strike at Japan from the Marianas, and to a lesser extent China. With Germany on the verge of defeat following Overlord and Bagration, Japan has no effective allies and no prospect of serious military, political or economic aid from anywhere. I'm not terribly familiar with the Japanese political situation at the time, and whether there was any hope that the western allies and the Soviet Union might be drawn into war against each other, but even then a continuation of the shaky Soviet-Japanese Neutrality Pact seems the most likely outcome rather than overt military aid.

From the Japanese perspective, you have to consider that they truly had little chance of winning the war from its inception in the first place, let alone recover in 1944.

Here's a post I wrote before about the military's host of functional issues:

There was much argument within the army over whether they should fight a long war or a short war. Even though long, drawn-out wars of attrition were a more modern form of warfare (which many Japanese military officers realized after their involvement in WWI), the faction that preferred to plan for a short, decisive victory gained more influence. Instead of improving technology and logistics and having less but more capable units, these generals who planned for a short war wanted more soldiers and more divisions. Instead of relying on more effective technology, they put their faith in having zealous soldiers who were much more committed to the war than the soldiers of other countries. Consequently, they heavily indoctrinated their soldiers to be ultranationalistic and supremely obedient to their officers and hoped that these hard-fighting soldiers would make up for deficiencies in technology, and the army instead opted to spend their budget on more soldiers.

So basically the way army officers saw it is they would surprise America with the bombing of Pearl Harbor and immediately rush into other places in Southeast Asia and take those, while the Navy captured a bunch of islands in the Pacific. Then they depended on Britain surrendering to Nazi Germany to scare America into surrendering to Japan to focus on fighting Germany instead. Their dependence on Germany is a big flaw, and the other big flaw is that this is about as far as their planning went. The army and navy were not in agreement on many matters, and the army was not completely unified within itself (one example being the short war vs. long war faction). There was no overall grand strategy when they bombed Pearl Harbor. Instead the army expanded in several directions, occupying as much land as they thought possible with no way to defend it (there was disagreement on whether the army should focus on North Asia or South Asia) and the Navy just expanded outward into the Pacific, a completely different direction than that of the army.

The military and emperor continued fostering hope throughout the war that they would have one, big decisive battle that would finally force the US military to the negotiation table. Their attempts to create this battle became more and more desperate as the Allies came closer and closer to Japan. The only plan they had to recover from their position was to build up an inordinate number of infantrymen, even including untrained civilians, wait for an Allied landing, and counterattack to the best of their ability.

Sources:

Drea, Edward. In the Service of the Emperor.

Drea, Edward. Japan's Imperial Army.