That is an example of how much Gold has already been reduced. It used to be Much Much more in previous versions. Many Players would have been in the Millions of Gold in treasury with 10s of thousands per turn at 100% research.
Gold reduction is an Ongoing process that will Not be complete until all parts and Projects are finally added to the Mod. Pepper2000's late game additions thru added Eras is still being processed, analyzed and an ongoing balancing act. And you have not even reached that part of the game yet.
Early Civics for early game I have been working on to reduce early game gold glut. But Gold Glut is different in the eye of each beholder/player. You see 100,000 treasury with 5000/turn in Ren as too much. Others do not. I see it as one modder (of many) working on balancing as evidence that it is coming down. Is it complete? Heck No! Will it get fixed I one fell swoop of the Modding axe? Again heck No!
And the Mid game is still to be addressed as well. But Thru Civics I can only get one stage of the game done at a time.
Also raxxo has recently (last couple of months) reduced All Gold % modifiers thru out the mod, just like his latest reduction to Culture. And this also dictates that all previous work on the early game has to be re-analyzed and the Early Civics reworked. Which in turn slows down the work on Mid game Civics. And Civic changes are but one of the points of reduction to Gold, Culture, Production, and Research in the Mod
This Mod is still an ever changing process and will Not be finished anytime soon.