Do I really need eARC for my basic setup?

I only intend to run 3.1 audio. Maybe I'll do 5.1 in the future but I doubt it.

The plan: Roku -> new Samsung TV -> old AVR (yet to be purchased). I'm thinking about a used Denon AVR (e.g. S710W, that sort of vintage) that probably doesn't have eARC, just ARC. I want the TV to be able to control the master volume on the AVR, output 3.1 sound, and that's basically it. Bonus points for an AVR that will sleep when idle, but I suspect that's not really ARC's responsibility.

Will traditional ARC be OK for this? I get conflicting info when reading about this and some people insist that it will be "bad" without eARC. I appreciate your advise!