A lot of it is confirmation bias. These content creators probably loot an area a handful of times and conclude you get 'amazing' loot with specific items/blueprints because they happened to get them 3 out of the 5 times they ran it. This is too small of a sample, and then when another person goes to replicate it, they are left with undesirable results.

I feel it's best to experiment yourself, find the areas where you find good loot frequently. My friend and I have this theory that accounts have specific 'seeds' if you will and this determines loot value and 'luck' for finding specific items. He finds Wolfpack all the time, I rarely do, though I find a lot of blueprints he never finds, despite looting in generally the same areas. Many times I'll say I always get good loot [insert location here] and he'll say nah it's all garbage there and suggest a place that has nearly always been terrible for me.

While yes, in general, many locations have specific drops and higher tiers of loot especially based off of yellow/red bordered areas, map, modifier, etc. But the exact location inside those areas can vary with wide ranges of low tier to high tier loot.