> Mac OS X had a yearly release cycle in the beginning if I remember correctly.
That's not correct. Here are the # of months since the previous Mac .0 release:
10.1.0 6
10.2.0 11
10.3.0 14
10.4.0 18
10.5.0 30 (delayed due to iPhone)
10.6.0 22
10.7.0 23
(Steve Jobs resigns)
10.8.0 12
10.9.0 15
10.10.0 12
10.11.0 11
10.12.0 12
10.13.0 12
10.14.0 12
10.15.0 12
This was a logical progression until 10.8. The fundamental software development principle is that immature software is easier to improve, because there's a lot of low-hanging fruit — glaring bugs and missing features — whereas mature software is harder to improve and easier to accidentally break. That's why major updates should come more slowly as the software matures over time.
It's no coincidence that Tiger and Snow Leopard are viewed as high points in Mac OS X quality and stability. It's not because of the .0 releases, which were very buggy like any .0 releases; it was because they ultimately became very stable after many many months of minor bug fix updates with no major updates (30 and 23 months respectively).
Also worth mentioning: major Mac OS X updates used to cost $129. Now they cost $0. You get what you pay for. Now users are pushed into updating whether they like it or not. You might wonder whether the principle starts to apply: if you're not the customer, you're the product. After all, Apple has been transitioning into a so-called "services" company. They'd rather sell yearly "subscriptions" (more accurately, rentals) than major OS updates.
> In my opinion, the drop in quality was probably at least also related to Steve Jobs‘ death.
This may be true, but note that the change in OS release schedule coincides with the death of Jobs. Mac OS X 10.8 was the first post-Jobs release and also the start of the annual schedule.
Thanks for the details. Just to be clear, I‘m certainly not in favor of the yearly release cycle. Or rather, I‘m not in favor of any primarily calendar driven release cycle.
FWIW, the update from (checks notes for the naming) Ventura to Sonoma is pretty much just a bugfix release, there were almost no noteworthy new features.
There's no such thing as a major bugfix release. Every major update introduces more bugs than it fixes, and Sonoma is no exception to that hard rule. Which bugs were fixed? I've personally filed multiple new bugs against Sonoma.
I wrote about this in my previous comment: "It's not because of the .0 releases, which were very buggy like any .0 releases"
In my opinion, the drop in quality was probably at least also related to Steve Jobs‘ death.