[DanielHB]

async-await is not the best solution for most things, but it is usually the best solution for UI and I/O (database interactions, data-fetching, file-system, etc)

Which makes it default-best for (and I speculate here) 90% of the code that is written because it covers client-side and server-side API layers. Ie business logic. Like you mention this kind of code is very rarely synchronous (in the sense that you want to block the execution thread until you get the result). An UI needs to keep answering to users inputs and an API server needs to keep answering requests while waiting on I/O

The places where it isn't good are usually the kind of software that can be packaged and reused (libraries, ie the heavy lifting software). Things like databases, image processing, neural networks, etc

Talking about JS specifically there are a few more use-cases where it isn't good even though an async-await system makes sense, like embedded low-memory environments

IMO the main problem with JS is not JS, it is the browsers DOM. It is about time we get a replacement.