I don't see the argument that it's weakening the JavaScript ecosystem. If anything it enriches it as you have (generally) safer more robust code to work with.
TypeScript is reaching GHC level of configuration flags, builds using it manage to even be slower than many native toolchains, and the team seems to just keep going with crazy type systems ideas, I already lost track of them.
Really, I hope that in a couple of years browsers would just allow for WebIDL integration and that is it.
It's quite common to see a similar concern raised about contemporary versions of the Swift language design (language-nerd lunatics taking over the asylum).
Really, I hope that in a couple of years browsers would just allow for WebIDL integration and that is it.