> I did try Debian YEARS ago and Firefox was out of date in quite a scary way. It's unclear to me if I did something wrong there, but badly out of date web browsers can also be quite scary. At the time, I never looked into and just went back to Ubuntu.

Was it missing updates, or was it just the ESR (LTS) version that only gets security (and maybe bug) fixes but is still maintained?

It was probably more than a decade ago, so I really can't say. I'm sure if I'd put time into, I could have resolved my issues.