Thanks for the responses. It seems like there may be convergence among many designs as they reach the performance limits of the DAC chips they're based on.
No, there’s much more to a DAC’s ultimate sound than the DAC chip — the power supply and analog output stage just to name two major factors.
Since the early 2000s either cheap DACs have gotten better than my ears, or they've gotten better than the rest of my equipment, or both.
Yup, in general they have gotten much better, and there are meaningful differences if your system (and ears) is up to it as others have mentioned.