... Or will the need for DACs be simply eliminated. I predict that DACs will eventually be used only in the esoteric realm ...
Unless there’s a return to the analog era - which is extremely unlikely - there will be a need to convert digital to analog. So, no, I don’t see a future without DACs.
A DAC converts digital to analog but a class D amp to my understanding does the same thing but with gain.
Most DACs have gain. I’ve never seen a class D amp that could apply Reed-Solomon error correction or follow any of the other digital transmission protocols, unless they had a built-in DAC, of course.