Which is a good reason to eschew software that's delivered via third-party servers versus running on your hardware.

Weird, I have some saved copies of sites that ceased to exist years ago. The backups are still where I left them and I can open without issues. Apparently Microsoft failed to wipe my backups.

Yes but I don't "own" a website. It's not reasonable for me to expect websites to keep working the way they always have.

For SaaS of course, that's something to be aware of. Since I don't have the hardware and software under my control, I have no say in when the supplier stops providing it. Many people have learned this the hard way with Google services, just as an example (there are many others, not picking on Goggle in particular here).