Stuff like Quake 2 and games that use its engine already run fine on Classic Amigas, and will gain more speed on A1s.
The OS is definetly programmed with modern 3D support in mind, but there's only so much the programmers can do within a reasonable amount of time. It's better to release a version without (modern) 3D support than not release a version at all and wait for everything to be finished, no?
I for one would rather have all printer/usb/etc stuff done before 3D things.