Programming and reading.
This would likely only hurt the end user. Many use chromium-based browsers, so you’re just driving those away.
You can detect Firefox, so you can do a superficial block in JS, but lemmy is such a simple site that you’d find it hard to find areas where there’s actual differences between the browsers, those usually only come from complex pages like video calling
Immutable distros aren’t immutable in the home folder though, they would be unusable otherwise, so that doesn’t solve OPs problem of dotfiles/personal files (I know nixOS tries to get rid of dotfiles, but in my experience that almost never works, it’s only helpful for replacing config files in /etc)
Ah sorry, missed that, yeah mobile screens are kind of identifying, not sure if any browsers get around that
For the screen size, it’s not actually the screen but the window, which is why tor browser opens in a fixed window size. If you just maximize, even though many use 1080p monitors, your particular settings of your DE give you away (size of bars, window decorations, …)
The main reason for Ubuntu against Debian is the packages. For Ubuntu, they’re much newer, and with PPAs (launchpad.net), you can often get more and/or newer packages built by other users. For debian, good luck, you’re stuck with old packages (which is the intent of Debian stable, but not nice as a user, that’s for server)