- PaaS for running WASM compiled untrusted web applications, especially nice for "edge service style PaaS"

- Node style async of rust, can be a bit more simple then rust-async (but also likely more limited)

- Similar "compile once run everywhere" as JVM (but better due to limited interface and server focused?), i.e. you have the wasm runner compiled for each target but you need to compile the program only once and then you can run it on all kinds of platforms including x86_64, arm64 etc. Especially good for PaaS but also good for more flexible deployment pipelines in large companies.

And especially for many web use-cases, especially as run on a lot of "edge" services the drawbacks of single threaded WASM do not matter much. E.g. the workloads are of the kind which tend to work very well with WASM performance wise.

In many ways, web development is like a single distributed application between client and server. So if you write your client code in Rust/Zig/C++/etc and emit wasm, wouldn't it be cool if you could share data structures and logic for that code on the backend that would handle client requests?

Once you're in this industry, you stop trying to figure out why fads come and go. There really isn't any reason. It's all fashion. You'll go crazy asking "Why?".