Then I started getting some crashes occasionally but still relatively rarely. This increased a bit around Sierra then reduced again with Mojave.
Then Catalina happened and with the new 2019 mbp retina, I started having crashes about once every two weeks. Now, I have an mba m1 running Big Sur, and I think my average uptime is around 2-3 days. Crashes are now something typical, I no longer expect my computer to run for long stretches of time. For a few months, my mba couldn't even go to sleep with crashing, couldn't restart without crashing, this was only solved once I updated to 11.6.1 (I tried reinstalling mac os x before to solve this, it didn't help)
So, yes macs used to be very stable but not anymore, I don't know what happened with Apple's QA but it seems there's now major issues. I didn't change the way I use my mac, if anything now I don't use SIMBL or kernel extensions (which I used to use back when my mac didn't crash) so things should be more stable not less. Yet, despite having ever more control over our machines, being more restrictive over what we can do, Apple somehow is making their system less stable, more flaky than before.
Of course, this is anecdotal, I might be very unlucky but in the past year, I've had quite a few coworkers drop out of calls or be temporarily unavailable, telling me that their mac crashed and they needed to reboot. So, it does seem to be widespread.