Assuming equivalent performance, which I understand might not be the case, is there merit to this idea? Or is there nothing new WASM provides?
That's the idea behind the Extism framework:
uBlock Origin uses WebAssembly in Firefox for better performance:
https://github.com/gorhill/uBlock/wiki/uBlock-Origin-works-b...
https://blog.cloudflare.com/announcing-wasi-on-workers/
I assume the merit for cloudflare is lower overhead cost per worker than if they had done something more like AWS lambda. Explained better than I can, here: https://developers.cloudflare.com/workers/reference/how-work...
It does currently present a lot of restrictions as compared to what you could do in a container. But it's good enough to run lots of real world stuff today.
It does not work with wasi.
I just use a simple driver:
https://github.com/syumai/workers
Wasi is so painful that I just write all my golang using stdio and have a shim per runtime. Web browser, Cloudflare, server ( with wazero ).
The new go:wasmexport might be useful in go 1.24 but I highly doubt by it.
Yes, this is a key value of WebAssembly compared to other approaches, it is a relatively (compared to a container or a full blown VM) lightweight way to package and distribute functionality from other languages, with high performance and fast startup. The artifact is minimal (like a static/dynamic library, depending on how much you've included), and if your language has a way to run WASM, you have a way to tap into that specialized computation.
Contrasted with WASM where you can write in any language and bring the ecosystem with you, since it all compiles down.
Bolstering your point -- smart-and-hardworking people are working on this, which results in:
https://github.com/bytecodealliance/componentize-py/
which inspired
https://github.com/WebAssembly/component-model/blob/main/des...
with some hard work done to make things work:
https://github.com/dicej/wasi-wheels
It's a fun ecosystem -- the challenge is huge but the work being done is really fundamentally clean/high quality, and the solutions are novel and useful/powerful.
In the sense that compiling C to any language is easily done without too many problems, what wasm allow is to have a secure and performant interface with that language.
For example IIRC one of the first inclusions of wasm was to sandbox many of the various codecs that had regular security vulnerabilities, in this Wasm is neither the first nor the only approach, but with a combination of hype and simplicity it is having good success.