As a frontend developer of 15-20 years now I've been pretty dumbfounded and unconvinced by any arguments for this style of css, I think it's especially hard for frontend developers of such duration because this is effectively the first ever style of css you write, and then you were force fed xhtml, semantic web and then later responsive became the "Told you so!" of the methodology.

Despite my scepticism of extremes of semantic web, I realise now when I read articles talking about switching to this style of css, their problems are entirely unrelatable to me because I implicitly see the conceptual structure of a design vs its visual specifics.

This just feels like a new age of developers don't see the need for the abstraction and so it's a constant mental burden for them without any benefit.. I think what has propped this up is that some of the problems that semantic css has historically only ever been able to solve (such as responsive) are now being solved differently, either through more powerful css layouts that implicitly layout better responsively, or that they rely instead on javascript to switch classes/html/components out with media query listeners.

Ultimately I think whatever you decide should be based on what your team aligns to best, don't feel guilty about 'not getting' this pattern, but I think it's important you pick one way, as mixing these worlds just doesn't work (at a project level), but certainly you should always try new things for new projects or experiments.