I realized why I enjoy Linux so much and why I've stuck with it all these years (slight vent)...

Did I miss something in the news about PC Express? Does their new update not support Linux or something?

That really depends on your needs, and the Linux distro you're using. Generally speaking, the greater your requirements (and therefore usage), the more finicky an OS gets.

I switched my non-techy Mum and Dad over to Linux over a decade ago (Xubuntu previously, now Zorin) and in all this time, I can count on one hand the number of times they called about an issue. The entire motivation to switch them over was because Windows was so unstable and would either tend to break after an update, or get infected by malware or something, and I got tired of being the IT guy for them and having to constantly fix it. I reasoned that Linux would be a good candidate for them because they have very simple requirements - they mainly just use a browser foe the most part, work with documents occasionally and do a printout once in a while, like for flight tickets and stuff. More than a decade later, my reasoning was proven right, and I'm glad it's been working so well. Linux was the very definition of "just working", at least for my parents.

Really depends on distro/use case/luck. I’ve had quite a few years without any issues, more with minimal and very rare irritations. The day-to-day experience continues is pleasant.

The few months have been somewhat more frustrating for me, and once I have a bit more leisure time I’ll switch distro to something that hopefully works better for me.

beyond one or two mistakes of my own doing, where i didn't read or think before running a command, linux is perfectly stable compared to windows for me atleast!

I've worked with windows professionally for many years, and have experienced far far more stupid inexplicable frustration with windows bugs than with Linux ones. Windows bugs are intractably unfixable and require arcane workarounds more often than not.

• KeepassXC should just work, if the browser's key was added to your KDBX database successfully. Other than that, I am surprised.
• Yup, the motherboard clock thingy is a consequence of Windows storing local time, vs Linux storing UTC. It's a minor thing to fix in any of these systems, though.
• Shortcuts thingy - never had a problem, although I did have a problem with KDE's keyboard shortcuts to run a program, which may be related workflow and maybe both were/are broken.
• KDE Connect is surprising, as at least for me it worked flawlessly
• The reboot thingy must be related to Linux Mint. I saw similar thing in EndeavourOS. One nice thing that some distributions implemented, is the ability to apply updates when you poweroff - from my point of view it's a less annoying solution than what you describe.
• I can't comment on the 'cherry on top' one without more details.
  I had a somewhat similar issue on my work laptop a short while ago, when I installed a program, which included a bugged XML settings file, then ran system update. When the updater tried to rebuild some caches (related to ie. icons, MIME etc.), some programs which use these caches simply stopped working. Reinstalling all packages with apt was the only thing that helped, to this day I do not even know all of the parts of my system that were broken.
  But this was one of these issues that happen once per 5 years, and leave you scratching your head and asking "what the hell is going on here?". The difference from Windows is that in Linux, you can have a high understanding of system's internal modular components (at the cost of time needed to learn it), and regular system issues can be identified after a few minutes of Googling.