> i think it's more that the massive engineering effort that's gone into improving JS has leapfrogged it over languages like Python, Ruby & PHP in terms of performance and tooling.

huge js lover here but I don't think this is true. I think the basic obvious progression is that the client side has shouldered more & more responsibility, that architectures have shifted away from being server side, & few folk have figured out how to make the server relevant. it does a tiny bit of business logic & mostly just crud operations on data. trying to do like we did, keep rendering & a lot of the client state on the server- it wasn't helpful, was a bad way of doing things. these choices of languages became irrelevant as the client side rose in prevalence, capabilities, & yes too, somewhat, performance, but mainly I chalk it up to a long long struggle to find suitable architectures. I don't think this is fair accompli, that it's all decided, but server side needs to radically change it's game if it wants to become relevant again.