Despite the author's obvious enthusiasm: WASM has a long way to go before it is really useful. From my humble perspective there was not much progress since the 1.0 release. As long as every access to the host (especially the GUI) is tunneled via JavaScript, one shouldn't be surprised about the low performance and the enormous memory consumption. See what happens behind the scenes when you set a pixel in the SDL API when running a WASM app in the browser. And there are plenty of good alternatives for the desktop already.
WebAssembly proposals tracker: https://github.com/WebAssembly/proposals
WebAssembly reference types (https://github.com/WebAssembly/reference-types/blob/master/p...) looks like the blocker for a lot of things, and it's in the final spec phase at least.
In Chrome, it's behind a flag since 78, which went stable in Oct 22 2019: https://chromestatus.com/features/5166497248837632 But also under active development? https://bugs.chromium.org/p/v8/issues/detail?id=7581
Supposedly implemented in Firefox two years ago: https://bugzilla.mozilla.org/show_bug.cgi?id=1444925
Nothing in Safari, of course.
Where is it now though?