I am keeping all e-mail tied to custom domain. If a provider goes down, I can just move that domain somewhere else. Yes, history will be lost, but new mails will keep arriving.
This isn't feasible for most people though. Hence why this exists. Not sure why that's so hard to understand.
Yes, we could set up our own mail servers, manage DNS meticulously, whatever. Most people don't have the time, and many people don't even use email that much anymore to begin with.
Not sure what the argument is here. Just because they aren't your preference, they don't work at all?
I'm guessing this is common practice, or tooling is available, but could you set up essentially fallback DNS to your own servers in the case of protonmail servers not responding? Should you have some middle server that does smarter routing based on the status of the final server? I guess you're nearly running your own mail server at this point, though.
I am leaning more towards just owning your own domain name, and using that for your e-mail address. I.e. configuring custom domain for e-mail. This way, if your current provider goes down (for the long run), you just go to a different provider, and configure your existing domain name for the e-mail. You don't have to change your e-mail address at all this way!
Yes, you could also run your own mail server, but this is not my point.
Yes, we could set up our own mail servers, manage DNS meticulously, whatever. Most people don't have the time, and many people don't even use email that much anymore to begin with.
Not sure what the argument is here. Just because they aren't your preference, they don't work at all?