I'm still on High Sierra on my 2015 Macbook Pro. I haven't upgraded my OS nor my machine and pretty happy with it (I only accept updates within my OS version itself) . On my home machine, I do use Mojave, which by itself is quite buggy and I'm waiting for some more fixes before I upgrade my Macbook Pro to Mojave as well.
I never install Apple's newer OS'es because I have a lot of development related stuff setup on my machines and wouldn't want them to break post an update. But so far, this lag in my update schedule has served me really well for years now and looks like this won't be changing anytime soon for me, either.
The "Regressions Get Fixed. Old Bugs Get Ignored." thought does not help your strategy.
After 6 months into the new version of iOS and MacOS, there is a lot less attention to fix problem in the previous version of the OS. It is even worse when it comes to firmware problems on older hardware.
If you have a 2+ year old Apple device you need to hope that all the security bugs on your hardware are also in the latest software or hardware, otherwise it may just never be fixed.
Google is just as bad at this and have many of the same issues of too many things being built at the same time. Googlers often lament that fixing bugs is never a priority to new features which is pretty much Apple as well. Perhaps too much complex technology is hard to do.
I work for a non-tech similarly big company that uses a lot of software (that we make ourselves as well as integrating vendors) and our processes and quality are even worse than Apple and Google.
But as an iOS dev I would happy if at least Xcode was built and tested properly...
Same here. The "You need a newer Xcode to compile this" pops up more and more often though (e.g. with vulkan stuff), so I guess I'll have to upgrade soon... probably to Mojave.
I never install Apple's newer OS'es because I have a lot of development related stuff setup on my machines and wouldn't want them to break post an update. But so far, this lag in my update schedule has served me really well for years now and looks like this won't be changing anytime soon for me, either.