Many things are possible that weren't possible before. For example, I was able to compile the Dart VM (the compiler + analyzer + VM) to wasm and run it on the web: https://github.com/modulovalue/dart-live it supports hot reload and many other cool features. It runs essentially everywhere and it's a very bare proof of concept for a fully integrated programming development system.

The problem is that things just take time if you have to coordinate across a bunch of languages and teams while trying to make everyone happy.

To give you a sense of what else is coming: the wasm ecosystem is moving towards supporting a component model. Eventually you'll be able to import any piece of code from any programming language that supports it. Wasm interface types will make that possible.