Good point. By the looks of the header of a PS “Paths to Illustrator” export file I’m guessing it’s writing Illustrator 3 files (at least in CS3 which I have), which, way back, used to be the most that everything that could import .ai files was able to use. That’s all that Adobe thinks is necessary to move some vectors from one source to another and is probably why Illustrator lets you save files as Illustrator 3 and then 8 and above in the Legacy choices.
Some wiser head described it a long time ago – To bring vectors in all you need is 8 (all you really need is 3). Illustrator is meant for 2D work and most of the effects and filters that have been added are not going to make much sense in 3D (what use is a Blend going to be in 3D?). If any 3D software company was willing to try and keep up with an updated importer every time a new version of Illustrator came out they would have to take programmers away from other features of the program.
I don’t know anything that does more (doesn’t mean it doesn’t exist) certainly Maya will import version 8 and Max’s manual says it imports Illustrator 88 (which is between Illustrator 1 and 2)…