My device always shows the WiFi number. It’s nice to know since I live in an apartment building with shared wifi. The shared wifi is 4/5 and mine is 6 so I can see at a glance if I’m connected right.
I can’t imagine another reason it’d be useful though.
I have a ThinkCentre m90q with an i3. It’s a few years old. It’s a lot more powerful than a Pi. A Pi will not cut it.
You will preferably need something with modern hardware encoding. Support for h265 and AV1 is a requirement nowadays to play high quality sources and find anything for newer stuff. Moreso if you want to watch 4k content.