Brilliant post. I'm the same age as you and used to be a software developer in a high-value industry. Our UIs always stayed broadly the same and only ever changed or added features in response to customer demand, not because some jumped-up marketing twat thought it would be a good idea to change it. Never took away features ever, why would we do that? Buried one once under an Advanced menu when we realised that too many novice users were accidentally screwing shit up with it, but never removed it.
Like you, this modern trend for changing everything all the time for no good reason is driving me insane, almost literally in fact. In the past five years I've lost (or had rendered unusable) my favourite OS, three of my favourite email programs (and the email address I'd had for 17 years), three chat applications (have lost touch with so many people), my favourite music player, several excellent and much-missed websites and doubtless more if I could be bothered to remember. The online world feels like it's shrinking, not expanding.
As a result it's actually got to the point where I'm starting to withdraw from techy stuff altogether... not bought any gadgets in years and my presence on and usage of the internet is becoming rarer and rarer and thinner and thinner on the ground. Am slowly shutting my accounts down one by one as I go, before they do it for me.
From a 15-year-old hacking together 6502 code on a Commodore PET, to this. I guess I got old.