> hardware

Sure x86 is an absolute mess, but I don't think it's a primary bottleneck. High end x86 cpus still beat high end ARM cpus by a significant margin on raw performance. Even supposing x86/ARM are bottlenecks... yeah a bottleneck at double digit billion ops per second.

> Languages unlock performance for the masses. Javascript will never be truly fast because it doesn't represent the machine.

C# and Go are already really fast (https://github.com/ixy-languages/ixy-languages) languages for the masses and at this point you can compile most things to WASM to get them run in the browser.