That’s in stark contrast to the current, mainstream Republican ideology which dictates that if Republicans lose, then the election must have been “rigged,” which is more like burning the whole system to the ground.
Also not trivial to design a law against it. Most common solution seems to be use of independent commissions, but commissions can also be “independent” in name only.
I have only ever seen examples of it at the Federal Election level, so wondering if your first point is actually completely accurate. (I believe the States themselves control the "maps" but forgive my ignorance if not)
Both are a problem. The latter just means that the State Congress can be artificially heavily tilted vs one party or the other.
Gerrymandering should be prohibited by the courts, but the current SCOTUS in its great wisdom ruled that courts must remain silent on the subject.