Wow, that's a sobering read, thanks! It's funny to see how some of the common gripes with modern "flat" design was so obvious even before it became mainstream. Even though it (in my opinion) looks better today, the skeumorphic, brutal, beveled Windows 95 UI was probably the most obvious and clear interface I've ever used.
Except for when those custom controls fail to implement all the features of the built-in ones, as the article details from various popular sites, at least back on 2016. But maybe at the end of 2021, all custom stuff is fully accessible and reimplements everything.