I think just frontend is a more apples to apples comparison. In that scope, what >10 teams >1m ARR are using plain Rails/Django html templates with html button

I think just frontend is a more apples to apples comparison. In that scope, what >10 teams >1m ARR are using plain Rails/Django html templates with html button actions and such? If you shop around at Rails/Django jobs, they're almost all going to be using different frontends that you'd need to ramp up on: React, Vue, jQuery, Hotwire, Turbo, Stimulus, HTMX, Alpine.js, etc. You could also say "If you know jQuery fast forward 9 years ago... you still know it" and be right about keeping yourself to the limited opportunities to do it the old-fashioned way.