It would be neat if the big companies like Dropbox, Instagram, Google, Oracle, Shopify, Stripe, whatnot building better Python/JavaScript/Ruby implementations would start building program analysis libraries for Python/JavaScript/Ruby so that more implementations could get this for free.

For example, the homepage of Nuitka says they only just added support for constant folding and propagation. That's such low hanging fruit it's crazy they have to do that for themselves.

You can imagine generic libraries for Python/JavaScript/Ruby that will turn the AST alone into its most optimal form and then let some other backend worry about code generation or VM implementation.