The lategame feels pretty sparse, just waiting and waiting for the income to buy several really expensive things. It'd help if there were additional things to spend research on, since there's a significant gap between the second-last research and the final one. Maybe researches to reduce the cost of all the ecological structures you're building?
Relatedly, you probably have a huge resource surplus in the late game, and are only waiting on money. It might help if it was possible to build a lategame resource export structure, to sell off all the junk that piles up.