The biggest problem to me is that there really and truly is only 1 way to reliably get science: Campuses.
I strongly suspect that the devs originally had this idea that the average civs will roughly have an average distribution of districts in their empire. Consider how they added the mechanism for less your common districts to be cheaper.
This works really nice with districts being a balanced affair. Roughly every 3 pops you get a new district slot in your empire = 1 more unit of empire power. But we have to deal with districts not being balanced.
Campuses are very strong, but they also come super early.
Ancient- HS, Encampment, Campus
Classical - CH, TS, EC, Harbor
Medieval - IZ

Further, every district gets its adjacency card roughly the era after it unlocks (point to campus) and get their t2 building 2 eras after they unlock in most cases (Another campus advantage.) Just delaying the non holy site adj cards to only start coming in medieval would be big.
I would much rather see the campus in classical, so the only real ancient district is the holy site. The other thing you could then do is tweak the cost of tier1 buildings to be more level. I've mentioned it before but they vary from 65 (shrine) to 80 (library) to 175 (workshop.) So they could definitely use some touching up there as well. The early unlock gives a pseudo discount to campuses as well since the can be placed earlier (and are thus cheaper.)
Now if you want to break the back of science spam that is a different discussion, but campuses themselves are definitely really really strong at every stage of the game. (Science spam is effective regardless of how good the campus is; it just happens to be the perfect source.)
Even going for a culture or religious victory, you still need to push science to avoid being a pushover.
I understand the demands of needing to keep up - you can't totally neglect stuff- but whats most frustrating about this is usually you do better at any victory if you campus spam. Similar to how any victory is easier if you take over your neighbor, except you can always choose to campus spam. And when you campus spam you can totally neglect everything else and still come out ahead (this grinds my gears the most.)
Sure, you get a couple points if you have Wats,
Side comment: I really wish they would touch up the religious buildings/beliefs a bit to round them out. Swap cathedrals to +2 culture. Add in a "monasticism" belief to give science a la choral music. We'd have to balance science first but I think it would be fun.