Which will probably break like crazy.
The issue with RV for many is not that you do not get enough. More that it is. Simplistic with no challenge.
The balance adjustment to not break it would be to give all the non-owners 50% of the follower belief and enhancer, so you actually might become interested in the religious game even if you didn't found a religion.
And I'm aware that the major complaint is related to the way RV develops, however, I agree with the OP, this is partially due to the fact that it is also unrewarding. And why is unrewarding? What do you get for putting effort into converting a city (and sometimes it is a lot of effort!)? Negligible bonuses. As I said, when you are military taking a city, that is huge. But when you finally managed to "convert half of a civilization" you get... well it is not about the bonuses, it is about the victory.
If the religious game turned into a legit way for bonuses, all civilizations would take part into it and, ideally, human players and AI would have much more reasons to Declare War and "Condemn Heresy" more often, turning the RV less "simplistic" because it would be much more related to diplomacy and war.
The religious game can't be solely about the RV, just like Science Victory also buffs the military and all yields of a civilization, Culture Victory and Diplomatic Victory also buffs the civic tree of a civilization, and Domination, that buffs everything about your civ (in a more unfocused way).