Like some, I find the religion aspect in Civ7 lacking.
But most importantly I find the lack of a benefit for converting your own cities to your religion a huge flaw.
You should be rewarded for actively making your own cities follow your religion, as it is now, there is little to no reason other than just denying the opponent their rewards, unless I'm missing something important here. But that is how I and several of my friends view it in this game.
For instance: Lets say you take the +4 to yields for each Wonder in the foreign city you converted.
This sounds great, but becomes completely useless when you realize that most players will build wonders in their capital and also make their capital their holy site, making it impossible to convert that city, rendering this choice 100% useless.
But what if it gave +1 yields for each Wonder in cities you own? It's not overly powerful, but you get some kind of benefit from it. The ones that say +2 of a yield? Give us +1 or +0.5 of that yield for our own cities. We should be rewarded for interacting with this part of the game on our own empire we took the time to build.