Haven't written much TS, so can't speak to that.

I should have made the distinction between client-side and server-side JS/TS. Familiarity and expertise will be a main driver of productivity for a team, regardless of language/framework. For us, that's RoR.

Client-side JS however has a multiplying property, where we often need to write more server-side code to accommodate the growth in client-side code. If the client-side code is providing undifferentiated value (e.g. authoring HTML), we now have more pieces in our system to accomplish our goal (author HTML). What's been surprising to me is that you don't need to author HTML client-side to have a reactive experience. With Turbo, Stimulus, and server-rendered HTML, a great experience is possible with fewer layers.