It's not available on every video. So if you're primarily using it for background noise, I'm assuming it's mostly like background music, which is less likely to be a video that qualifies for the improved bitrate.

As mentioned, it was introduced a few years ago. It really makes a noticeable improvement to video quality, too. Bit rate is kind of king when it comes to streaming.

For whatever it's worth to you iirc they didn't downgrade the original bitrate, they just introduced better bitrate and locked that behind the subscription.

I don't personally pay for YouTube Premium anymore, but I did for a while. I consider it an incredible value, tbh, but stopped because I wanted to stop supporting Google.

However, I also just don't use YT anymore as a result. I'm curious how you think YT should exist if not by charging for features? Because I'll be honest, of all the enshittification YT has experienced, this one in particular is way, way down on the list for me.