I've tried go, rust, c/cpp, webassembly.
go - big bundle sizes because of gc I am guessing, idk.
c/cpp - I haven't touched c/cpp in a really really long time, but probably the other really good fit.
rust - I see rust as the successor to what I would've used c/cpp for, but not sure if rust ecosystem is still fully there. Last time, I had some weird issues with wasm-bindgen.
AssemblyScript(AS) - Something I really like and what I am most comfortable with now that I've been doing java/c#/ts for so long now. Also it's geared towards wasm which is nice. It's my favorite solution, but I don't really get it like I get the other solutions because everything else is an "actual language" that's used for other things. I am really not sure what the strict ts stuff is about, the devil is in the details, and this is getting way too high level.
c# - Maybe good if someone is heavily invested in .net.
At the end of the day, these wasm blobs are probably for heavy tasks like functions with a lot of loops, not full systems, so any simple solution would probably work. It's why I like AS (or even cpp), but sometimes these tasks require some niche external libraries in which case rust would be probably be the best option.