I hope we don't bloat up wikipedia pages with too much whitespace. Getting of borders, "minimal" looks bother me so much because they're sacrificing layout for aesthetics. There is a reason why borders exist. It is a line segment that separates logically laid out content into groups.
I want Wikipedia to stay the same even if it is not ideal. There is a lot of legacy and "learned" behavior.
We need to add the familiarization factor to any UI changes. The amount of changes should at the minimum exceed the accrued familiarization of the UI...the longer the design remains the same, the higher this factor. It is crazy to think that we should not make a change if it is for the better, but there are a lot of people ... millions that use this less-than-ideal UI. There is something to be said about that.
Typographically, Wikipedia pages have too wide of a column width. This is a common problem not just with webpages, but with magazines and newspapers. There is a reason why the dimension of a book (such as a novel) is smaller than a magazine and that has to do with how wide of a column is comfortable for reading. We need to look at how magazines and newspapers solve this problem. They use columns. Larger fonts is not the answer nor is excessive whitespace because you're not solving the layout issue. It is just magnification.
If newspapers didn't exist and if web designers today were tasked to design a physical newspaper, it would be bloody 80 pages long and full of massive margins and fonts with no understanding about density of presentation. The web needs to be treated like physical media (yes, I said that, fight me). It is a rectangular 2D space that presents text - no difference to my retina whether it is a magazine, newspaper or LCD monitor in terms of spatial representation (not talking about contrast/backlit aspects). This was different a while ago, but today, the pixel density is great and we can almost treat monitors like paper (again, not talking about backlit issues).
Web designers today won't be able to design a physical telephone book. It would be called "Too overwhelming" for the user and it would be insanely big in 17 volumes.