Cannot place or link native AI file into document if PDF compatibility is off...
AI files cannot be placed into other AI files if PDF compatibility is off for the linked files. PDF compatibility completely negates the benefit of linked files storage savings since a complete duplicate of all artwork (included linked assets) gets embedded with the AI file - this is inefficient (at an extreme level) Illustrator should be able to place native AI files without relying on PDF and we should be able to benefit from the storage savings of linked assets.
Yep, the fact Ai can’t place files in it’s own format is just stupid.
It’s like we were not able to use smarts in Photoshop (although I believe it is based on having a flatten copy displayed instead of the full stack) or pre-compose in AfterEffects.