Web Assembly is one of the more misunderstood technologies in terms of it's real, practical application.
At its core, it crunches numbers, in limited memory space. So this can provide some 'performance enhancements' possibly for running some kinds of algorithms. It means you can also write those in C/C++, or port them. Autodesk does this for some online viewers. This is actually a surprisingly narrow area of application and it still comes with a lot of complexity.
WA is a black box with no access to anything and how useful really is that?
Most of an app is drawing 'stuff' on the screen, storage, networking, user event management, fonts, image, videos - that's literally what apps are. The notion of adding 'black box for calculating stuff more quickly' is a major afterthought.
At the end of the day, JS keeps improving quite a lot and does pretty well, it might make more sense to have a variation of this that can be even more optimized than building something ground up.
WASI - the standard WA interface is a neat project, but I feel it may come along with some serious security headaches. Once you 'break out of the black box' ... well ... it's no longer a 'black box'.
WA will be a perennially interesting technology and maybe the best example of something that looks obviously useful but in reality isn't really. WA actually serves as a really great Product Manager's instructional example to articulate 'what things actually create value and why'.
It will be interesting to see how far we get with WASI.
For 5 years we've been hearing about how great they are, except nobody is really using them.
So now, it's 'the next thing' that will make it great? Except that next thing isn't there, not agreed upon or implemented, we don't know so many things about it?
Like I say, this is textbook example of tech-hype for things probably not as valuable as they appear.
If (huge if) WASI were 'great, functional, widespread, smoothly integrated' - I do agree there's more potential. But that this will really happen is questionable, and that even if it does happen, it will be valuable, is questionable.