What you just said doesn't change the fact you painted an inaccurate picture. Will Shopify ditch Ruby one day? Maybe...not likely imo but maybe. For now there's zero signs they're doing that. They're investing tens of millions of dollars in Ruby as I said ... I looked at their JIT team and these guys don't come in cheap. I have no idea what this Remix purchase means but I find it hard to believe it's about rewriting everything in JS.
As for the JIT progress here are the stats https://speed.yjit.org/. I think they've been working on it for around 1.5 years they're definitely not done. Its not fantastic yet but almost 40% faster is nothing to sneeze at. If JS became fast why can't Ruby or Python? What you said about Dropbox is interesting, why is Dropbox the ones making the effort? They are not that big. There are huge companies running millions of lines of Python code - Instagram is a Django app and Google probably has a bunch of Python. I'd expect these companies to make the effort ...guess there's no economic incentive yet.
As for the JIT progress here are the stats https://speed.yjit.org/. I think they've been working on it for around 1.5 years they're definitely not done. Its not fantastic yet but almost 40% faster is nothing to sneeze at. If JS became fast why can't Ruby or Python? What you said about Dropbox is interesting, why is Dropbox the ones making the effort? They are not that big. There are huge companies running millions of lines of Python code - Instagram is a Django app and Google probably has a bunch of Python. I'd expect these companies to make the effort ...guess there's no economic incentive yet.