My websites would fare a lot better unstyled than most websites built on top of frameworks like Bootstrap and their 'classy' HTML, but it's still not going to look good without CSS and no online business is going to make more money without CSS than with it.
I'm a big fan of terse, straightforward HTML, plus nice CSS on top of that. I've made (and get a lot of use out of) a basic.css stylesheet I built that supports a few basic themes: http://staticresource.com/basic-test.html
That package contains more than just basic.css, but also includes three additional styles, and a bunch of simply written responsive CSS + JS plugins as well.
Not quite. I block javascript with NoScript. I block many third-party requests with RequestPolicy. I block webfonts with uBlock. I have disabled anti-aliasing/font smoothing (almost completely) in Windows.
Some websites make me glad Palemoon still has the View -> Page Style -> No Style option. I do admit a day may come when I do disable CSS once and for all.
Unfortunately, as people write more and more convoluted html, and are using javascript techniques for laying out web pages and blogs, not just web applications -- it's becoming harder and harder to have the reading experience one wants, rather than the reading experience some designer fop thinks you should want -- for no good reason.
It started with Microsoft Frontpage setting the background to white without overriding the body text colour by default (so those that had a user stylsheet for reading white/light text on a dark background got zero contrast) -- and has been going steadily down hill from there.