Counter anecdote: I’ve been using Linux for 20 years, nearly half of that professionally. The only time I’ve broken a Linux box where it wasn’t functional was mixing Debian unstable with stable, and I was still able to fix it.
I’ve had hardware stop working because I updated the kernel without checking if it removed support, but a. that’s easily reversible b. Linux kept working fine, as expected.
I’ll also point out, as I’m sure you know, that the BSDs are not Linux.
Funny, i broke my Debian twice (on two separate laptops) by doing exactly that, mixing stable with testing. I was kinda obliged to use "testing" because Dell XPS would miss critical drivers.
In fairness, this is the number one way listed [0] on how to break Debian. That said, if you need testing (which isn’t that uncommon for personal use; Debian is slow to roll out changes, favoring stability), then running pure Sid is actually a viable option. It’s quite stable, despite its name.
I’ve had hardware stop working because I updated the kernel without checking if it removed support, but a. that’s easily reversible b. Linux kept working fine, as expected.
I’ll also point out, as I’m sure you know, that the BSDs are not Linux.