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. :)

Beginne mit dem Abschnitt Rules of Hooks, insbesondere mit der bestehenden Erklärung zu bedingten Hook-Aufrufen. Füge falsche Beispiele oder Klarstellungen hinzu, die Hooks in Schleifen und verschachtelten Funktionen abdecken, einschließlich der Unterschiede bei benutzerdefinierten Hooks, und betrachte die Arbeit als erledigt, wenn diese Fälle in der Dokumentation klar erklärt sind.