I've been seeing a few links to Strudel recently so I went digging to see how old the project is - looks like it launched in April 2022 https://loophole-letters.vercel.app/strudel
It came out of the same team as Tidal Cycles, a Haskell live-coding music tool which was first released around 2009. https://tidalcycles.org/docs/around_tidal/tidal_history/
Such a good example of why everything is becoming js. Because it's where the users are. Anything that isn't in js will just languish comparatively.
Everything is becoming js because everything is becoming js.