I mean yes. We've hosted internal apps that have four nines reliability for over a decade without much trouble. It depends on your scale of course, but for a small team it's pretty easy. I'd argue it is easier than it has ever been because now you have open source software that is containerized and trivial to spin up/maintain.

The downtime we do have each year is typically also on our terms, not in the middle of a work day or at a critical moment.

I've seen gnarly code everywhere, from kernel drivers to desktop applications to web apps. At the end of the day this describes most of computing imho.

I'm guessing they are giving the core away for free to collect training data.