I once worked on a VK mini app with one guy. He was building the app itself, I did the backend. He just recently started learning web development, having never done any programming before.

So I'm ready for him to test my backend, I tell him to make a request to https://... and pass this and that parameter. And he just has no clue what I'm talking about. He somehow managed to learn React, a bit of HTML and a bit of CSS without any of the underlying basics. I had to explain him some of HTTP, the URL structure, and what an XMLHttpRequest is.

This was a revelatory experience for me.

I once had a co-worker admit he wasn't always sure which code ran on the server and which in the browser, in a PHP/javascript app that didn't use nodejs.