A browser that can run multiple agent-controlled sessions at the same time basically turns multiboxing from a chore into a one-click experience. My productivity may not improve, but my game progression definitely will.
My point is here: There are many popular AI-Friendly PL, eg. Python, Rust ...
I also see many CDP-based framework which implemented by Python-Binding libs, They works very well.
I think javascript is not the only option.