I agree with the first part, with the caveat that, if that’s what was going to be the case, it should have permanently ended after Boo.

If the series continues after that, it needs to be Goku, because Gohan is boring as shit on his own. His character only works in contrast to Goku, and that difference was seemingly intended to be done away with after Elder Kaioshin’s training, hence the symbolic adoption of Goku’s gi.

Goten is a non starter. He literally has no character except as a straight man to little Trunks. It has to be Goku. I really don’t think going back to Red Ribbon type stories is viable in a mainline arc anyway. You have characters that can effortlessly topple mountains by blowing at them. Those early stories worked because everyone had limitations, that doesn’t exist anymore.