I have more faith in WASI. Linux containers is inherently in a whack-a-mole position where they're trying to retrofit security onto something that was never built for it, which very rarely works.

There's a huge performance hit for many programming languages when you run them inside a WASM runtime. Memory also behaves very different from normal applications. Autovectorizasation also isn't universally supported by WASM compilers yet, which can be costly for performance.

Properly configured WASI runtime are great for security but they're worse than containers on most other fronts. I don't think the downsides make sense unless you're building a business that lets random customers upload WASM files you execute.