There is research out there that shows use of white space can improve things like reading speed and comprehension.
An example for text paragraphs: https://www.semanticscholar.org/paper/Reading-Online-Text%3A...
I think it really depends on individuals though. If you can memorise a dense screen of buttons you'll be able to work faster, avoid scrolling etc. But it'll make the UI harder to use for people who don't use it regularly.
Ultimately, every UI has to strike a balance. If you do it right you'll piss off both sides equally.