

Minority browsers. Since I daily drive Pale Moon, I’m among the people affected. It’s suspected that they test only the 3-4 most popular browsers, and whether anything else works with their code is up to luck.
You may think browsers with tiny market shares aren’t important, but all new browsers start out that way. I fear for Ladybird if it ever makes it past the alpha stage, for instance.
Gentoo is quite happy to allow you to copy your
world
file and config files from one system to another, then just issueemerge --emptytree world
and take a couple of days’ vacation somewhere while the system rebuilds itself as specified. That’s been an option for as long as I’ve been using it, so at least 20 years. Other than the speed, the only issue is that you have to know where to find all the config files, of which there may be many distributed across/etc
and~
(and maybe other places if you’re really unlucky).(Figuring out how to word the
emerge
command so that it downloads as many binary packages as possible to shorten the wait is left to the interest of the reader.)