My experience with FOSS has mostly been that mature projects with any reasonable-sized userbase tend to more reliably not break things in updates than is the case for proprietary software, whether it's an OS or just some SaaS product. YMMV. However, I think probably the most potent way to avoid problems like this actually ever mattering is a combination of doing my updates manually (or at least on an opt-in basis) and being willing to go back a version if something breaks. Usually this isn't necessary for more than a week or so for well-maintained software even in the worst case. I use arch with downgrade (Which lets you go back and choose an old version of any given package) and need to actually use downgrade maybe once a year on average, less in the last 5