WASI has been in Preview1 for a couple of years now, indeed. However, Preview2 is well underway and the initial implementation is scheduled to land in wasmtime this June.
without these we can't compile our favorite apps in our favorite languages
lets help get these into preview2 so that WASIX is not needed anymore but until then the community needs an interim solution that has long term support - that is WASIX's complimentary goal.
https://github.com/bytecodealliance/wasmtime/issues/6370