I had the feeling that "quite a few" of the assets I have purchased on the Unity Asset Store were deprecated but never really took the time to actually check out how many. My feeling would have been "probably 10% or maybe 20%". But in fact, it's: 224 assets of 673 assets are deprecated! ... and I don't blame the publishers: The pace in which Unity adds new implementations (often of features that already existed), that are not compatible with existing approaches, then implements them to about 80% or 90% "complete", then starts something new, drops support for the old implementation, rinse, repeat ... well ... it's tough when you're developing a game, but even much worse when you develop for the Unity Asset Store. The good thing is that some of the deprecated packages do still work, even in current Unity versions. But still, using packages from the Unity Asset Store does add quite a risk to any longer term project.