A lot of people who think of themselves as able-bodied never think to poke around in the Accessibility sections of their settings menus. But it turns out that accessibility options are for everyone; people should really think of and evaluate them as first class tools more often

They really should just have a single checkbox, "Prioritise usability over wank", and leave it at that.

That's an interesting idea: if you're thinking of having an accessibility option, consider just making it the default.

Or,are we just getting older and these things suddenly matter?

A button looking like a button isn't an age (of the reader) thing.

Of course it is. What should a button on a screen look like, after all, it has absolutely nothing to do with a large mechanical button from the 80s the old designs tried to emulate. In fact, such buttons are becoming rare even in the physical world, the younger generation is more and more accustomed to touch buttons for operating all kinds of machinery around them. So "like a button" is very much an age thing

Looking like a "touch button" is still looking like a button. Some indication that an element is tappable is still useful.

Game consoles are still pretty popular, I don't think people are going to forget what real buttons are for at least another couple of generations.

Possibly a factor, but I also think these issues are becoming much more widespread, leaving us less able to tolerate them than when they were less common.

Nah, one of the things I found in Discord's accessibility settings is an ability to turn off or reduce animations and other visual effects by default, which is wonderful no matter your ability.