I'm a game dev, and I work on high-performance websites in my spare time (e.g. https://noclip.website/#mkwii/beginner_course ). It's actually possible to make stuff that runs fast in "mostly-compatible VMs for a dynamically-typed scripting language never designed for anything more important than making buttons light up when you hover over them" if you actually try. But Google does not, so we end up with gmail.