Better HTML would go a long way, for that matter. It's pretty dumb that there are millions of independent implementations of payment forms for the Web, for one thing, and that most depend heavily on javascript to function well. Simple table sorting—should be built-in, probably since 15+ years ago. Proper memory-efficient list elements, like native toolkits often feature, should be available in pure HTML. So much wasted effort because the Web took over but no-one ever bothered to make it, you know, good for all these things we're now using it for.
People vastly underestimate DX, unintentionally gatekeeping technology while feeling like they "sticking it to those pesky Devs who overengineer everything!!!"
