To add onto your excellent comment: Another lifesaver for me is the 'gi' command, which focuses your cursor on the first text input. Saves a lot of mouse movements.

For me personally the browser was the last application in which I had to use the mouse, vimium solved that. Sounds like a mundane application but after a serious hand injury it made the difference to me for working 4 hours with mouse and being in pain, or working 8 hours pain free.