I still think that this kind of approach it's only a "problem moved" from CSS to inline HTML, which makes me mad because i still need to jump from HTML to CSS all the time, plus custom modifications can be painful with tons of overrides and "!important"s. Exactly like bootstrap.

BEM (with none-to-few utility classes) was a game changer to me (even if far from perfect) and its most natural conseguence are web components.

I'm loving the Bulma approach BTW.