[Albert_Camus]

>And it's a breeze to figure out and read the code too: even when it's 10s of thousands of lines of code.

Not at all. The issue with an application written in jQuery is a lack of sane state management. Forgetting to initialize (or re-initialize) values, not expecting things to be executed in a different order, and just poor organization in general led to mountains of runtime errors.

Nowadays we use Elm. The difference is night and day. I wrote a post on this topic a few months ago: https://charukiewi.cz/posts/elm/