I don't think science buildings should be buffed besides the Research lab because it is trash. If we buff them, we're going to end up not building other districts anyways. Libraries and Univeresities are already more than beneficial for their cost as they get buffed by the Great People so much. This is another reason why IZs lag behind-- Great Engineers are by and far inferior. But in any case, I think campuses will be built anyways.
The other thing is too many regional effects would encourage even more city spam, and that already is so much of a thing.
In any case, I want to type out the other
changes I'd make to the districts, though they weren't concerned with the topic of production at hand. I guess it needs to interact as a whole
Entertainment District
Entertainment Districts also give +2 loyalty to the city
Arena-- +2 Amenities, +1 Culture to this city
Zoo-- +2 Amenity to all cities in range, +1 Amenity to this city for each camp owned by this city, +2 Amenities to this city for each National Park owned by the city.
Stadium-- +2 Amenties and +4 loyalty to all cities in range. +4 tourism and +1 Amenity to the city if it is pop 10 or higher, +1 amenity, and 10% tourism to the city if it is pop 20 or higher, and +10% gold, 2 amenities to all cities within range if the city is pop 30 or higher.
Maracana-- +2 amenties to all cities. All cities on the continent Maracana is on that are ecstatic receive +10% to all yields. Removed Stadium requirement, only requires Entertainment Complex.
This is pretty obvious. Entertainment buildings take forever to appear, and +1 amenity from zoos is downright sad. The concept of the stadium is great though, but needs to do more. Maracana probably still won't matter, but at least it'd seem more like a trophy.
Harbor
Lighthouse: +2 food and 2 gold to all sea resource tiles owned by the city, on top of whatever exists.
Shipyard: Also add +10% production to ships
Seaport: Also add 10% food to the city.
Colossus: Also add +1 production to all coast tiles owned by this city
Great Lighthouse: Also add +4 combat strength to naval units on all ocean and coast tiles owned by this city
I honestly think Harbors are fine the way they are. They don't get used that much, but work fine when needed. Maybe Great Admirals could be buffed though.
Theater Square
Art Museum and Archaeological Museum-- +4 Culture
At Cultural Heritage, Great Works +2 gold (stealth buff England low key)
Broadcast Center-- +20% culture to this city. +2 loyalty to all cities within range
Bolshoi Theatre-- +20% culture, Offers 2 Civics of your choice and 1 random inspiration.
Broadway-- Also, +50% culture. This city receives gold and tourism equal to twice this city's theater district adjacency bonus.
Hermitage-- +100% culture from Great Works of Art in this city. When a Great Artist is recruited, these yields are doubled for 5 turns and receive a random inspiration. +100% Great Artist points from this city.
Sydney Opera House-- +100% culture and tourism from Great Works of Music in the city. When a Great Musician is Recruited, these yields are doubled for 5 turns and receive a random inspiration. +100% Great Musician points from the city.
Theater Square buildings are already really good at what they do, but tourism is one note. Yea I know the suggestion the Broadcast Center is a bit sketchy with overlap, but I really doubt that will cause anyone to spam Broadcast Center, and I just like it for some flavor.
The cultural wonders though, are all kinda crappy except for Bolshoi, and the randomness from that is no fun either. I think making them city specific would allow for some fun for tall players, especially with Reyna but won't affect strategy in the long run. You might even build them for a non-cultural victory
Campus
Research Lab-- Also +10% science, +2 Great Scientist points (Actually I was too lazy to type it, but all t3s need more great people points)
Oxford University-- 1 Free tech of your choice, and 1 random tech, +50% science to this city.
Amundsen-Scott-- Also, 100% science to the city it is built.
As I've implied before, Campus buildings are more than fine because of the countless great person boosts they get. Only Research labs really need any love, and Oxford while good, could be better since we don't really have a "Science CIty" in this game.
Amundsen-Scott is actually rather good already; it's just that it's hard to build. Buffing the all city bonus I think would be too crazy, but so an additional local bonus would be nice for the city you wasted a settler on. Overall, I'm against buffing science on a grand scale for the most part as it will inevitably lead back to the status quo.
Commercial Hub
Bank-- Also +1 Gold to each land tile that has a yield of at least 1 gold already
Stock Exchange-- Also +20% gold to this city, and -10% to gold purchases from this city
Well, while some Merchants can be buffed, I actually think Commercial hubs are in a good place but the later buildings don't really have any utility besides a bit more gold and that often doesn't matter. The Stock Exchange is particularly pathetic, but overall I think the hub and its associated wonders are fine for what they do despite not necessarily being "meta" Hopefully nerfing science/culture projects will already put them into contention. I also think Big Ben is too ... wait no.
Oh whoops, I forgot Holy Sites existed
Holy Site
Shrine-- Also +2 faith if this city is of your majority religion
Temple-- Also provides gold equal to the Holy Site's Adjancency bonus. This is doubled if the city follows the religion you founded.
Worship Buildings -- All provide +20% faith and -10% off faith purchases in addition to what they do already.
Mahabodhi Temple-- Also, Cities that you convert for the 1st time gain 100% faith for 10 turns.
Kotoku-in-- +50% faith to the city, this city can produce warrior monks
Potala Palace-- Also doubles your current faith stockpile. Acts as a Holy City for Religious Pressure if the city is of your religion. (must be founded by you)
What can I say? You either build Holy Sites or you don't so you should be able to rewarded for investing in a religion. In particular the Worship buildings aren't really that great especially for the faith they cost. There's actually some good religious wonders in the game like Hagia Sophia and Mt. Michel so I left them alone though Kotoku-in is so hilariously bad. And yes, I know Potala Palace isn't really a religious wonder, but it sucks and I think it should be buffed.
Overall, I actually really doubt the fastest players would change their playstyle at all, and even those these wonders look OP on paper, I have a feeling it's still going to be beaten by optimal players running my (nerfed) projects.
But for those people that want to drag on the game a bit or if the AI gets better, it may at least make the late game less boring. As long as the AI isn't able to actively threaten you past t50, it really won't matter what I write.