How could/would candidates fund their elections if outside group funding was not allowed?

1. How could/would candidates fund their elections if outside group funding was not allowed?

2. Should outside funding such as PAC’s be allowed?

3. Does outside funding make a difference in political races?

https://www.npr.org/2022/10/22/1129976565/dark-money-groups-midterm-elections-republicans-democrats-senate