As much legacy code as has been written in C++, I'd think a total rewrite might be better ironically, in terms of passing on important institutional knowledge, to the extent large-scale production codebases are concerned. Attacking it bit by bit (pun not intended) might even take longer than just ripping things up and starting anew.
I just know I'm a bad engineer. No matter how hard I work to understand things like JS, large scale file organisation in a production codebase confuses me. Why is this a component? Why is this code in app.js and not in a component? Why do these things appear in this position on the page? Note that I'm still asking this with 3 YoE, so I don't feel great about myself haha.
Hasn't it been proven unsolvable?