Yeah it probably is in terms of an off the shelf, purpose built option with no tinkering. They're pretty snappy as well. Decent hardware in there it seems.
We have an ATV but our wireless network is kinda shit and we kept having connectivity issues between the ATV and the Plex server we were running on the Mini so we just went all in on running the Mini as the media player and Plex server in one to avoid it. Bonus was that we now have a very capable console game emulator hooked up to the TV too. Also we just ditched our last streaming subscription so all we were using the ATV for was the Plex app.
It's a bit overkill but I will say as a server and emulator the new apple silicon minis are great. Zero fan noise ever and they sip electricity and run really cool.