Wasm is more open, because we effectively have 1.5 browsers left, and whatever google decides will be the de facto “web standard” everyone should follow. If google were pushing for a slightly revamped jvm/applet model, that would be the standard (as the JVM is as open/standardized as it gets)
I don't buy it. WAS is still open from the start, and incredibly more simple and thus easier to implement securely.
And no, for reasons stated before an applet model would never become the standard again. You'd rather have to integrate Java with the browser so it's entirely under your control, and considering how massive it is and how hard it was to properly sandbox it, nobody in their right mind would decide on this. WASM reuses a lot of infrastructure already there, it's simply the best solution from a technical standpoint.
