I've used Blender only a little, but surely you're aware of the Asset Browser introduced in the 3.0? They seem easy enough to use, but of course they'd need to

I've used Blender only a little, but surely you're aware of the Asset Browser introduced in the 3.0? They seem easy enough to use, but of course they'd need to be high-quality to work similarly with all renderers. Granted I don't actually know where to find such libraries except for the small free asset bundles at https://www.blender.org/download/demo-files/#assets https://www.blender.org/download/demo-files/#assets or perhaps by paying Blender organization for them, so maybe this doesn't really address your core point :).