You know, we may be to specialized to see that normal users that are in majority do not care. Of course you may argue that page load and responsiveness is important in regard to the conversion metrics, be it so, but imagine some average non IT person. Your mother in her seventies. A high school friend. Your auntie. Do you think they care what technology is used? Certainly not. I've seen sites that you would label ugly and from 2000's, but they just work, users can use them easily. And I have seen a rewrite of such old site to modern js framework and it was a disaster, owner was sued by users of the site as they were missing profits because the site was slow and cumbersome.

I think the question is, who do you write the site for, for others or to satisfy your ego and show off?