Are you saying that web developers are writing the best code that they can? That future gains are going to come from more advanced js preprocessors instead of more informed developers? I strongly disagree that we have reached any sort of diminishing returns when it comes to the quality of hand written code.
> Between WebAssembly, SharedArrayBuffer and Atomics, and maybe even threads in JavaScript, the building blocks for the next generation of web applications are falling into place.
Read the specs for one of these. Read the specs for any of these. Read the specs for js functions you call every day, and image what the native implementation looks like. The web will never approach native performance because w3 has been sabotaging it for a decade.
> time to learn how compilers work.
I think the author would benefit from learning about how web frameworks work, or perhaps how web specs mandate that your browser works.