I am a big fan and user of keyboard shortcuts, and web apps make using those either weird and inconsistent with what you'd expect, or simply impossible. A user interface without support for keyboard shortcuts is not viable for productive use imho.

Web apps built with modern frameworks often can't even be used by Vim plugins in the browser, either because scrolling doesn't work, or the frameworks and scripts do so much black magic in the background that not a single button in the GUI is recognised as clickable element by the Vim plugin. Broken by design.

Not to mention all the performance issues and productivity blockers thanks to tracking, no support for right click(and its context menus) etc., instead we get animations which also add input lag to everything because it looks fancy.