I have been thinking about ways to increase GP output in the later game because imho they become too rare after the medieval era.
My idea: increase base :GP: with techs.

For example
4 :gp: instead of 3 :gp: from all specialists after the research of Education

+1 :gp: from World Wonders and National Wonders with Nationalism

+1 :gp: from Scientists with Scientific Methods

+1 :gp: from Merchants with Corporation

+1 :gp: from Artists with Liberalism

+1 :gp: from Priest with Divine Right

+1 :gp: from Engineers with Steam Power

Not a bad idea.

The "pool all GPP" mods might also be useful -- as it stands, the GPP production from secondary cities becomes non-useful after a few great people.

+1 :gp: from Priest with Divine Right

Coincidentally, this is roughly the point at which Great Prophets become useless.

Not a bad idea indeed!

Jaca

Coincidentally, this is roughly the point at which Great Prophets become useless.

And hence makes Divine Right an anti-useful tech.

And hence makes Divine Right an anti-useful tech.

It wouldn't make it anti-useful, you only get more prophets than usual when you use priest specialists.
I see that Divine Right is a bit late, but Theology or Priesthood are already important enough.
Btw: Great Prophets can lightbulb Liberalism and then become useless.