The binaries produced just for the engine itself (so exluding the game code and assets) is already several MB large when compressed with brotly or gzip [1]. So it works, but it's too large to be competitive enough on web games portals. Most players will just go play another game if it takes too long to load (download).
Only JS based game engines and to some extend Defold are good enough in this regard.
[1] https://github.com/godotengine/godot/issues/68647