I had some pretty strong pressure applied to use Typescript for pianojacq.com but resisted it for a very simple reason: no tooling other than an editor reduces the barrier for contribution so much that it makes it possible for outsiders that just know Javascript (a large multiple of the ones that know TS) to contribute to the project.

It also means there is no 'development environment' as such, it's just a repo on gitlab that anybody can read, fork and contribute to from within gitlab if they want.

I have also tried to keep the number of dependencies to an absolute minimum, which also helped to make something that doesn't feel like a moving target.