It is thought that the earliest mention of the people of Israel is in an Egyptian inscription of Pharaoh Merneptah (c.1200BCE), so some 200 years before the first king of the united monarchy, Saul. The text only makes passing reference to Israel as a group of people and probably located somewhere in the Palestinian region.
I believe the next known outside reference to Israel is in an Assyrian text telling of the coalition made by the local rulers at the battle of Qarqar in c.850BCE. One local leader being 'Ahab the Israelite'. This text was written after the death of King David & Solomon, and by this stage Israel and Judah were two divided kingdoms.
My question is: Was Israel so insignificant, that even during the civilization's 'golden era', during the reigns of David & Solomon and all the great building works they constructed, that they have no mention? Even the two passing references that only acknowledge the existence of the Israelites are written before and immediately after the prosperous period of their history.
I understand that more is written about the Israelites during the Babylonian and Assyrian invasion, from the record of their capture. But it seems strange that nobody thought to write about any relations with Israel, be it trade or any other communication.
Part of the answer is that most people stopped being interested in the area. The Egyptians gave up campaigns in the Levant around 1175 until Shoshenq around the early 900s (who is mentioned in 1 Kings 14 although some dispute this), and New Kingdom pharaohs didn't name their adversaries (certainly Shoshenq didn't). The Assyrians never ventured that far either until 853 so are unlikely to make mention before that time, and they like the Egyptians very rarely named those they encountered (no Assyrian source names anyone in Philistia, Transjordan, Israel (north or south) or Phoenicia between 1200-1050).
Of the remaining sources of perhaps lesser powers, most of them are concerned with their own local affairs - the neo-Hittite kingdoms make no mention of Canaan or Phoenicia. No Aramean inscriptions exist from before the 9th century save Tell Dan and Melqart, and no administrative texts either. Phoenician texts tend to mention only their own kings, and they tend to start only around 1000 BC.
There are a couple of possible mentions of David, Tell Dan (841), Mesha (840), and Kitchen makes a case for the possibility that Shoshenq mentions "Dwt" at Karnak which he suggests might be David, but even if it is, it's still only in the 900s.
Why nothing is found is Israel should be paralleled to "what have we found in Israel regardless?" and the answer is "not very much". Jerusalem has been heavily rebuilt and destroyed numerous times over the centuries and only a tiny part can be excavated, and even those areas are fraught with disputes (cf the Temple Mount). Samaria has produced no official inscriptions and that is from a much later period. The parts of texts we have found have been serendipitous in that they were smashed and used in building rubble.
We can also ask "what is found elsewhere in the Levant?". Aram-Damascus existed for 200 years but left nothing behind. Damascus has revealed no Iron age inscriptions (and I think parallels Jerusalem in that respect). Moab has only left 1 stele (Mesha's) and one other fragment. 3 small pieces exist from the kings of Ammon, none commemorating the Edomite kings. So nobody else has left very much behind.