replied to earlier:
Absolutely! I think separating HTML, CSS, and JS into separate files was a mistake. Web components would have succeeded far more if they had gone with the single-file component idea that so many web frameworks are converging on. I think it barely made sense in the Web 1.0 days — certainly not in the era of Web applications.
continued:Separation of concerns — Locality is more important. Code that changes together should live together.