The newer Class D amps are superior to most vintage amps & receivers. Regarding vintage solid-state amps & receivers, the 1960s and many 1970s used all discrete components. The receivers & amplifiers around 1975 and later started using op-amps in the audio circuits that were not good sounding. New solid-state designs have higher performance op-amps.
I use a vintage Yamaha CR-220 that is good sounding & quite a deal for under $100. But, my tube amplifier is superior. And, not all vintage or new tube amps sounds good. I rebuild the tube amps with superior coupling capacitors and use select tubes for best sound.