I don't really write huge complex types in TS, I basically stick to just the native data objects like string, number, boolean etc., but even then I find it so useful just for the autocomplete that you get out of it.

I jumped into some code I haven't touched in half a year the other day so had 0 recollection of any of it, thankfully cause of the types I knew exactly what to pass where and what to expect back without even having to read any of the code other than the type definitions.

I love me some dynamic languages, but damn if it isn't nice to have that kinda power available to you.