There is also the matter of separation of concerns, not wanting to add classes specifically for particular bits of code where possible to avoid it, but given the sea of classes generated by frameworks these days I'm not sure that is an ideal which is much followed ATM.
I think you touched on an objective subject, however, if you were alluding to performance. Classes are generally free and cheap. I’d be very interested in evidence to the contrary if anyone could share.
My last, somewhat random, thought is that it does indeed seem that who likes TW and who doesn’t does seem to depend a lot on the stack they’re thinking of when they mull over its (de)merits.
It isn't as much about performance (the small amount of extra network transfer is likely to be brought close to zero if compression is used, the extra CPU load might be measurable on low-spec devices but on top of all the junk already in sites using heavy frameworks this is not going to make/break anything) as maintainability. You have something extra to make sure is set everywhere it needs to be.