I use Youtube on deck in Firefox with youtube.com/tv in kiosk mode. Works really well, but I noticed even when I have a bigger screen connected I can only watch videos in up to 720p. It doesn't let me select anything higher. Is that a YTTV thing or is there a problem in my setup?
Not to be snarky, but welcome to the true frustrations against corporations. They view linux users (like you now) as pirating monsters, and in their eyes giving us even 1080 means that they're giving their content over to pirates. Which is ironic because I think that sort of behavior encourages pirating.
So it's nothing you did, nothing is broken, it's functioning as Netflix wants it to. It'll be the same with all of the other providers.
You're right, subbed in Netflix for some reason - but Youtube TV though acts in the same way, I don't believe they allow anything > 720. Free youtube is different, paid Youtube TV will throttle
I've got a legion go with Bazzite installed and now I'm curious. I'll boot into windows after I boot into Bazzite and see if there's a difference. At least then you'll know if it's Linux or YouTube.
Edit: So for me (granted I'm not on a steam deck but on steam OS for another handheld), it defaults to 720p but I'm using Firefox in desktop mode, and I have the option to change it to 1080p but only if I use a mouse to have over the video and select settings from the progress bar.
In windows (on the same device) it works just fine, and I can do 1080p premium on Firefox from windows 11. So it may be something stupid like needing to use the track pad, or it may be how you're using Firefox in steam OS (as an app inside steam or some other way).
Edit edit: Randomly the sound quality is quieter in Bazzite (receiver and speakers set to the same volume level) than in windows, by a significant margin.
Try resetting your Firefox profile. Sometimes a weird setting can break browsers in spectacular ways.
This was a big one for me, for the longest time I could not figure out why I couldn't get YouTube to play videos over 1080p for me in Firefox on my PC, it ended up being some weird setting that I changed in about:config (I sadly cannot recall which one) a long time ago - but I'd always copied my Firefox profile with me so that bad setting stuck around.