I use Ungoogled Chromium exclusively for YouTube, cause my graphics card csn upscale videos and convert them to HDR, but not in Firefox. The moment I get those features in Firefox, I'm done with Chrome for good.
There's a video service my therapist uses that refuses to run in Firefox. I expect it probably could, but it's a lot less work to just launch chrome for that one use case.
I'm saying that you log in as "jojo" to the computer and another account is called "jojo's gf". You can do whatever you want in each and won't bother the other. Computers are designed for muiltiuser use.
It doesn't bother either of us to be using the same login on the computer. And it doesn't really bother her that firefix is installed nor me that chrome is.
And since chrome is sitting right there, it's the easiest way to use my therapist's video service.