From what I've read [1], Flash was initially accepted, but then gradually hated more as [2] problems became obvious.
Could the same be true for the adoption of "Web Assembly"? Besides using the Javascript runtime and sandboxing, they seem like they may have similar problems in the future like; running binaries, compatibility, security updates... just like Flash did... but maybe this time it's different...
[1] https://thehistoryoftheweb.com/the-story-of-flash/
[2] https://www.granneman.com/webdev/graphicsmultimedia/multimedia/flash/whatswrongwithflash