Why iOS 13 and Catalina Are So Buggy
"No need to go into the details here, except to say that, apart from a few specific areas, Apple doesn’t do a lot of automated testing. Apple is highly reliant on manual testing, probably too much so."This tells you everything you need to know about the poor state of Apple's software. A large, untested code base that's been in development for years and years is going to reach a maximum point of complexity where the cost of adding new features exceeds the business value. The ROI turns upside down. That's when your technical debt turns into a bankruptcy and your software is kaput. It's quite conceivable that Mac OS, which is built on top of NeXTStep OS which dates back to the mid-80's, is reaching this state.