Although the Tailwind author hates @apply and says they shouldn't have put it in the tailwind in the first place (mainly because it's a hard feature to develop - i wouldn't be surprised it would be removed). I think going tailwind only is bad too because you loose many of the nice functions of CSS like theming/cascade.

So i think using utility classes/tailwind for base/layout and still using named classes where it makes sense (like common reusable components, hover hiearchies, transitions/animations) is most practical approach. And using BEM as convention for the named classes is not a bad idea - certainly better than no system.

I would say that'd be a Tailwind anti-pattern, since Tailwind exceeds by trying to do away with cascading, and BEM is an attempt to componentize CSS but retain some cascading.

Also, if you handed me a project with that approach, I would run for the hills! How would you decide when to use BEM styling and when to use the tailwind classes? It'd be a nightmare.