Thoughts from my 14-year-old backup Thinkpad T430 after the main laptop died:

* Github's javascript UI is SO SLOW
* Most of the rest of the web is actually not terrible (at least with adblock)
* It drives a 4K screen surprisingly well
* Video playback is bad
* How is this thing running out of RAM, it has 12GB...
* The keyboard is a delight

So it turns out that Ubuntu's Firefox Snap blocks Firefox from reading the system memory pressure, which it uses to work out when to reclaim memory by hibernating unused tabs.

Nobody thought to check why this kept getting blocked by AppArmor until someone pointed it out, and it still hasn't been fixed.

@russss snaps are why I left Ubuntu woth zero regrets.
@janl unfortunately this was what was installed on my backup laptop from a while ago, and I wasn't really in a position to reinstall it when my main laptop died! It is an interesting experience...
@russss good luck with it all!