I have been using Mac's since 1986 long before most of the people at Apple were born and quite a sophisticated user. Why does Apple allow young wizbang kids to write code for their operating systems. There are so many common sense and much more user friendly ways to do things. They are so caught up in expanding every possible thing a Mac can do and adding feature after feature just for the sake of adding something that they lost sight of how to make using a Mac simple intuitive an easy like it should be. Not only that both MacOS and IOS change and (many times not for the better) that just about the time you have figured enough of it out, they change the way it operates again. It is maddening and of course the people at Apple forget that not everyone works at Apple or is a geek. This is a big world with 300 plus million just in the States and the vast majority are not geeks. They need something that works in a common sense manner like when you save something the folders you want to save in and have been saving in all afternoon appear in the save dialog box. This one if a hundred things that are brain dead obvious if you actually use the computers to work rather than play. Every iPhone I have had butt dials like crazy, starts playing music or a youtube or moving from some web site on its own out of the blue and when you set an alarm the alert goes off in three minutes to a completely different alert sound and continues to change ring tones and you want to throw the damn thing in the garbage it is so frustrating. These are but a few of the extremely annoying and unnecessary bugs in the way both operating systems work. But do you think anyone from Apple would ever read what people say and take it to heart. That will be the day.
Like you, I have been using Macs for over 30 years. The first Mac I used was a Macintosh Plus in 1987. Since then, I have used nearly every version of the Classic Mac OS, OS X, and now, macOS, iOS, tvOS, and watchOS. The fact is that Apple's software engineers are not all "wizbang kids", but most probably are. What's wrong with that? Younger people can offer meaningful ideas to the development process. Most of the people working on the original Macintosh were "wizbang kids", including the man who ran the Macintosh project. Two "wizbang kids" started the company! "Wizbang kids" created the NeXTStep OS, which was the basis for Mac OS X, and later, all of Apple's current operating systems. I have loved every version of OS X, and macOS. There have been some feature changes that have annoyed me, or have not worked right for some reason or other, but on the whole, I have been very satisfied with everything Apple has done for the last 20+ years or so. Can macOS use some tweaks to make it easier to use? Absolutely! Pretty much all of the problems you described in your post are fixable, or at least can be dealt with using some tweaks. Not everyone has the same problems with Apple's products that you do. Not everyone needs to be a geek to work with these products. If someone won't learn the new products, that's their choice. My 72 year old mom proved that older people who are not "geeks" can definitely learn how to use new versions of macOS, iOS, watchOS, and tvOS, as well as new Apple hardware. All it took was her desire to learn, and actually trying to learn. I work as an Apple systems engineer for a managed IT service company here in Dallas/Fort Worth. I work with a lot of users from novice to power users. Somehow, they all seem to be able to embrace change, no matter what their level of technical proficiency or age. You have legitimate gripes, but it seems that you believe that we all have the same problems. We don't. Call AppleCare. Go to an Apple store if you live near one, and get the problems taken care of. Hopefully, you'll get help from an older Apple employee instead of a "wizbang kid".