As someone who works in security, I don't personally recommend self hosting your password manager unless you're planning on never opening it up outside your network or you're willing to be on top of all potential security issues. These are your account credentials we're talking about. You WANT them safe, and the people paid to make sure they stay secure are likely going to do a better job than you.
All 64 but cpus can run 32 bit processes just fine, and many distros enable multilib, or have some sort of alternative (e.g. SNAP) by default. Only distro I've had to do that on is arch... And that's a DIY distro, so that makes sense.
A preference for digital media and requiring someone to edit a file then recompile the project are two different things entirely. I don't care for star wars and wouldn't care what images they had from those movies, but even though I'm a dev and absolutely could build the source if needed. I'm quite likely not going to care enough to do that. A user that has never messed with source code is likely not going to be comfortable doing all that.
You gotta remember that your average user isn't a dev. They aren't someone who's used to modifying configs to set something up. They're more like your grandmother who isn't even comfortable looking into the settings app on their phone.
As someone who works in security, I don't personally recommend self hosting your password manager unless you're planning on never opening it up outside your network or you're willing to be on top of all potential security issues. These are your account credentials we're talking about. You WANT them safe, and the people paid to make sure they stay secure are likely going to do a better job than you.