To be fair my reference browser is Firefox, WebGL is a fair bit slower there.
What blows my mind with this technology is little things: porting the game to the browser gave me a half-working mobile port basically for free (had to implement touch input handling in Neverball). On top of that, thanks to SDL2 and the game controller web API, I can attach a game controller to my phone and play the game in the browser on my phone with a game controller. It just seems unreal that this combination of technology just works.