I think the point is only certain use cases (usually related to number crunching like crypto, but undoubtedly games too) may see substantial improvements, they still aren't close to "native" speed, and nearly all other use cases won't see much if any benefit, especially compared to the additional complexity of another language, compiling to was, etc.

Plus things like competitive games and what I'll call "pretty" games have to squeeze out as much performance as possible, and no hitching is acceptable to competitive games, which IMO means WASM is still a no-go for those types of games(although games that don't have this requirement undoubtedly benefit)