Still there have been periods when Receivers were flagship components, at the pinnacle of their respective brands ranges... big high powered, high performing ....
And then there were periods where receivers were viewed as the integrated, cheap, mass market component, to be sneered at by "true audiophiles".
The former category, continue to be desirable today, and garner more vintage collector cred. over time, the latter... fade away and are best forgotten (typically underpowered, power ratings in PMPO only, flimsy construction, variably reliability, etc...)
The big flagship Denon's are examples of the former category over the last 20 years... and with the new AV1h they have come back with a new generation...
Onkyo used to be a player in the quality receiver stakes, and their recent release of the RZ70/LX805/DRX-8.4 shows they are ready to play at that level again. (after a bad patch from 2008 to 2014 with major manufacturing/reliability issues).
The rise of AV and HT has revived the integrated multi-function receiver category... while silly pricing policies have substantially reduced the AVP category!
It would be nice to see quality AVP's come back into the mid market, the Marantz AV10 is lovely... but at its price point, there will never be very many out there.