SRE here, it's currently happening in a few parts but overall, it's not as attractive on server side. Server Side code running is mostly a solved problem and for very few organizations, the benefits of WASM don't outweigh any difficulties in getting it running.
> Server Side code running is mostly a solved problem
I know what you mean here, but I think we're very limited in what we tend to run. Polyglot programming still isn't really a thing, and with things like WASI standardized (someday soon I hope), I could imagine it becoming a lot nicer.