Unfortunately for power users, "one design to fit all devices" is done by designing for mobile first. Desktop is treated as a giant tablet. Hence the large buttons and huge distance between elements.

I don’t share OP’s gripes with the changes to Wikipedia’s UI, but there are approaches to responsive design (which one might phrase “one design to fit all devices”) that don’t arbitrarily hide useful stuff in a menu where there’s space to accommodate it. And those approaches have only gotten more capable in recent years.

The problem, if there is one, is information hierarchy and deciding whether/how/where to disclose a given information at a given level in that hierarchy and how it’s disclosed. It’s very situationally dependent and probably impossible to please everyone. Optimizing it for the best outcomes for most users is what most good designs do, and they very seldom do the things a lot of vocal HN complaints want (shove everything on screen close together with small text, ie optimize for desktop power users; or make everything infinitely configurable, ie optimize for… idk even what the optimization serves, the same users complain about the web being overly complicated).

That's a pipe dream if I ever saw one. Desktop and mobile inputs have entirely different properties and constraints.

And "one design to fit not maximized windows on not high-dpi screens."

The new design vs the old design.

https://imgur.com/a/rV1UXc4