To reduce the rapid expansion of Gold, the early Civics are a bit more restrictive in ramping up the Tech rate in the Early Prehistoric Era.
Prehistoric Era takes longer to get thru now. Calendar will not catch up for awhile.
If you are also using the Upscaled Research and Production Options then it will be even more noticeable.
The "Too Much Gold" Train is being slowed Down.
The Prehistoric and early Ancient are the only times when there is not too much gold. But before you could stay in the starting civics to avoid being gouged by the exorbitant costs on the later ones. Also, slowing the tech rate does not slow the accumulation of gold relative to era. Ie., if you achieved the surplus gold mountain in late Ancient before, you still will, even if it takes 500 more turns to get there.
Playing through early Prehistoric recently, I didn't notice there was more problem with gold than usual. The tech slowdown wasn't noticeable either, except in that suddenly I'm running out of buildings to build - I don't remember that ever happening before. Then again it was a faster speed (Epic) than I've played in a while.
The main thing I notice is having way too much hammers - seriously it feels like buildings could be twice as expensive, and stone throwers could be three times. I know there's an option for that, but firstly, I shouldn't be forced into that, and secondly, if this issue goes away in Ancient, the option doesn't.
Also should mention, production overflow gold seems to be more efficient than Meagre Wealth, which would be a bug.