Interesting to see this progress, and unlike the myriad of other web based software looks like they've done a pretty good job of making it feel native like in the browser. I don't feel too threatened by Godot's progress here, fortunately our engine occupies a fairly specific niche that doesn't overlap too much with Godot's market and would allow them to co-exist.
It does look a little heavy (12.5mb transferred/77mb resources to load cold) and is slower to load than I would expect. Doesn't appear like HTTP2 is supported which would probably speed things up nicely.
For anyone wondering what's the point of this, browser based software is incredibly beneficial to educational institutes especially in the Covid environment - we for example are getting educational institutes who typically use Unity and other software moving to us because it's far easier to get remote classrooms set up with their wide variety of devices students have at home.
I do think the future of software is in the browser. There are just so many advantages. Not to everyone's liking of course but I do feel it's inevitable. We went web only as it has the huge advantage of one code base to maintain, I would assume a large risk on Godot's part here is having to maintain multiple code bases.