Note that it only works in Chrome b/c it's the only browser that supported PNaCl (recently deprecated). Edge Beta (with chromium underneath) is buggy, so best not to use it for this tool.
> MacBook Pro (13-inch, 2017, Four Thunderbolt 3 Ports)
I wonder why PNaCL was deprecated if it is faster in run-of-the-mill situations?
Per wikipedia , other browsers rejected PNaCL because they don't like the idea of web apps running binaries as that represents a black box for most users. In comparison, wasm is "more open". Wasm code has a human-readable text equivalent (although, frankly, the number of people who will be able to make sense of it is not high and doesn't include me).
Here's an example of some mutex operations in WAT: https://gist.github.com/devsnek/9274f1420b7641d1b6c34141921f...
This is something that will easily improve over time without a ton of work.
There was even a WWDC 2019 talk, on how it allowed a seamless 64 bit transition for watchOS.
Also, performance is just one factor. Other criteria include security model, standards and governance, Web integration, nondeterminism.
web assembly is not necessarily just for the browser though. you can have webassembly without any web, just to run binaries across different platforms. i think it's pretty cool