For this very reason I switched for TS for backend as well. I'm not a big fun of JS but the productivity gain of having shared types between frontend and backend and the Claude code proficiency with TS is immense.
I considered this, but I'm just too comfortable writing my server logic in Ruby on Rails (as I do that for my day job and side project). I'm super comfortable writing client side React / Typescript but whenever I look at server side Typescript code I'm like "I should understand what this is doing but I don't" haha.