Not a full answer but in case you get no other replies i will try to give some input:

Western allies. Great Britain and the USA:

Both put quite some emphasise on their bomber arms. Both countries thought that bombers could have strategic effects and even end wars on its own. Very early in the war both countries decided that its from utmost importance to destroy German industry and therefore damage German capabilities of sustaining a war. Both countries were in a far different position than Germany. Great Britain for example had far less troops employed than Germany or Russia. The British army wasn't able to contribute to war effort in the same way the Red army did. Being pretty safe on the island Great Britain tried to damage the German war efforts without direct confrontation via ground troops. Strategic bombers provided this possiblity. The Battle of Britain showed the importance of the airforce when it came down to defending the country. The British airforce got higher funding than the Luftwaffe in relative terms. The British implented their ideas of stragetic bombing and build a strong stragetic bomber fleet.

Germany did not value bombers the same way the western allies did. Before the war the Luftwaffe had strong proponents for a stragetic bomber arm ( long range heavy bombers) but the Luftwaffe failed to implement these ideas, mainly because the persons in charge were not able to find a consense. Germany had a bomber arm but eventually put more effort into building tactical bombers to support ground offensives. The well known Stuka dive bombers are a good example for the Luftwaffe doctrine. The Luftwaffe doctrine was often more of a tactical and operational nature than a strategic. Destroying enemy armored forces was the main goal and not destroying the industrial capabilities of the enemy. That doesn't mean the Luftwaffe didn't understand the concept of bombing the industry of the enemy they just choose to distribute the ressources differently. The Luftwaffe was in a different situation than the RAF or USAAF. Tactical bombing > strategic bombing.

It should be noted that the different countries had to deal with different situations. While its easy to question the German decisions in regards to their airforce you have to consider the objectives they had in mind. Germany tried to win a land war against the Russia. Building a strong air superiority fleet which could enable ground attack aircrafts and protect the ground troops from enemy attacks was maybe a better choice than building a huge bomber fleet which couldn't reach Soviet factories anyways how could have insignificant effects against Great Britain.

Some numbers:

The US ratio for bombers to fighters was about 1to1

The German ratio was about 2 fighters for one bomber or ground attack.

Hopefully i was able to give some input.