Explanation on what can go wrong if Hooks were called inside loops or nested functions?

The Rules of Hooks section states that the first rule of Hooks is to only call hooks at the top level, i.e. "Don’t call Hooks inside loops, conditions, or nested functions". Later in the section, it explains what happens if we put a Hook call inside a condition. This still leaves me with some questions/doubts though. Are there examples where something can go wrong if Hooks were:

• called inside a loop?
• called inside a nested function? Furthermore, isn't a custom hook just a nested function? 🤔

I've tried to dig into some related questions on Stack Overflow here and here, but the answers provided only give the correct examples, but not the incorrect ones.

Could you provide incorrect examples for the other two cases? Or at least a little bit clarification would be most appreciated. :)

Commence par la section Rules of Hooks, en particulier par l’explication existante des appels conditionnels de Hooks. Ajoute des exemples incorrects ou des précisions couvrant l’utilisation des Hooks dans des boucles et des fonctions imbriquées, notamment en expliquant en quoi les custom Hooks diffèrent, et considère le travail comme terminé lorsque ces cas sont clairement expliqués dans la documentation.