Hi Mike, just a point of clarification, a 'cd player' hasn't changed. 20 years ago, a cd player had a transport and DAC built in, just as it does today. The same way an integrated amp from 20 years ago had a preamp and amp built in, just as it does today.
DAC's became popular in the 90's, as folks went to digital seperates, just as folks go from integrated amps to seperates. I think the resurgence of vinyl, along with issues that came up from digital seperates such as 'jitter' and/or clock problems have led many back to cd players today. You can certainly still find digital seperates today, but they are not as widely used as they were in the 90's.
Cheers,
John