I like the structural type system, but it's not my experience that the power of it is unquestionably a good idea to use for long lived projects. The simpler something is, the easier it is to maintain.
Agree, but I think it excels at it's intended purpose, as a "gradually typed" system where types can be added at the various places, and inferred types that "meet in the middle" will structurally type as intended. If you want to simulate nominal typing in places, you can always use tagged unions, as TS now offers several different ways to do this. (However, this info will typically not get erased at run-time, so you get reflection whether you like it or not :))