It may well be the case that they are all topologically equivalent, but they needn't be, so long as bridges are allowed. Perhaps that's how they could make F1 more interesting.

Suzuka has a bridge:-

https://en.wikipedia.org/wiki/Suzuka_Circuit

Unfortunately, the presence of a bridge is necessary, but not sufficient. Think knots.

In theory, theory and practice are the same. In practice, they are not.

Even circle tracks have tremendous local variation from a racing point of view.