I’ve been writing TS for a year now and I find TS annoying. Especially for react components with state management of some kind, the types get so complex you almost need unit tests to assert they are what you think they are. Additionally, TS being a structural type system with no access to nominal types at all eliminates a whole class of “ghosts of departed proofs” modeling techniques. (And, I know you can work around this, but those workarounds are ugly.)

My view is that I’d use TS if I have to but I’d pick either plain JS / CLJS or something like purescript if I really wanted types.