I sort of agree, but there are some function signatures that don’t match what’s in the code using @types/three, and mrdoob does not want to maintain this.
This gives a few @ts-ignore, but that’s not a big problem:)
https://github.com/mrdoob/three.js/pull/15597
There's some discussion in there, but the way I read the conclusion was they were going to be bundle the typings going forward.