That being said, "white spaces" are not supposed to always be the color white. Interfaces are not supposed to always be a sea of nothingness either.
That's simply bad minimalistic designs you are describing.
Even a skeuomorphic design filled with textures and gradients require good use of white space and a minimalist approach to be a proper UI. Function over form should remain true no matter the "skin" of your user interface.
I've gone back to making a home page (remember those?) for my Maths teaching next year. I'm trying to pack as much as I can into one page that students can just access without passwords and which will work ok on a variety of platforms.
I suppose this is 'maximalist'. Still no javascript. The style sheet is copypasta from various sources I'm afraid.
Intellij does this well since you can toggle everything with the key map, two key strokes and I have the conventional busy IDE interface, two more and editor with text and no clutter, which mode I'm in is dependent on what I'm doing.
vscode has it as well, they call theirs Zen mode.
I agree an information-dense approach is warranted when people re-visit a site many times-- what you would call professional/industry design? But even then, the minimalist principles are still valid. You don't want to clutter with unnecessary stuff, but you _MAY_ just have more stuff.
Do you have a compelling example of effective non-minimalist web design?
I'm so sick of consumer-focused web design infecting all corners of web design, including and especially professional/industry design where more information may sometimes be better than less. It's like UI designers' collective takeaway from Tufte et al. is "wow showing lots of information effectively in limited space is tough, let's just not do that."