To JS developers' credit, writing modern JS in many ways already is like writing a distributed system.

Even if you stay fully client-side, you have bits of code that are running in different parts of the browser and you have to marshal data back and forth between them. Many web API functions are really RPC calls into a different browser process.

JS has has primitives like channels, promises or async/await to deal with those.

At least there might be some ways how you could use those as as building blocks for an RPC system which lets you handle the three problems better.