I'm sure it depends on the city. I reported several large potholes in my city via an online form, and was disappointed to see them unrepaired for several months. Then one day I came and found that they'd repaved the whole street for 50m.

Yep, this kind of stuff can be extremely complicated because there are a lot of layers.

Potholes have different causes. For example if there is a slow water leak that's compromised the road sub base that needs to get fixed first or you're just throwing money in a hole.