As I mentioned, an AV Receiver is basically an AV Processor with built in power amps (for at least some of the channels).

Many of them have connections allowing you to start with one, but later bypass the internal amps and use your own external amplifiers. This gives you an upgrade path. External amps can be as powerful as you like, and can be superior to the tiny ones packed into the receiver.

Dedicated AVPs often cost as much or more than typical AV receivers, which might indicate how little is spent on those dinky internal amplifiers. Or it could mean that they know they can gouge you, knowing that you are about to spring for several outboard amplifier channels.

Nowadays, home theater devices support far more channels than is easily installed in a typical room. I still get by with a minimal 5.1 system (left center and right front speakers plus two surround speakers and a subwoofer.) I don’t miss helicopters flying over my head. AV equipment sees to go obsolete quickly. If you are willing to forgo additional channels and Dolby Atmos, etc., you can get a real bargain on an older processor or receiver.

The other thing to be aware of about older ones is that their video switching may not support the latest HDMI signals. In my case, I just do the video switching on the TV itself. It’s less convenient (requiring two remotes), but a hell of a lot cheaper than replacing the processor with a current one (I’m running McIntosh gear, and their latest AVPs cost is stratospheric.)