Fun thing to know - commented out code is still a node in DOM tree (with nodeType: COMMENT_NODE), so there shouldn't be a need for regex (if that's done via regex)
I'm not a fan of React (and not use it at work), but imagine that you have multiple login forms, either to same service or to different ones. With React (or any similar JSX framework) you can embed such form component in your application = it will behave the same way in any place you put it in (or can be customised dependent on the parameters). Then it can also be tested that it behaves in a certain way and conforms to business rules.
OCRs don't hallucinate outputs = if it says "212.99mm" on architecture diagram it doesn't suddenly turn into "2413m" on the other end, because LLM thought this feels better. I remember reading on HN where that was happening in a such case (but sadly my google foo fails me to find a link)
The case you might be thinking of is the JBIG2 implementation bug [1, 2] in Xerox photocopiers where the pattern-matching would incorrectly treat certain characters as interchangeable, leading to numbers getting rewritten in spreadsheets.
Depends on the subject - I can remember multiple subjects where the teacher would give you a formula to memorise without explaining why or where it came from. You had to take it as an axiom. The teachers also didn't say - hey, if you want to know why did we arrive to this, have a read here, no, it was just given.
Ofc you could also say that's for the student to find out, but I've had other things on my mind
