Scaramanga
Brickhead
On the contrary, very good for gameplay, adds more variety. The main reason the late game is boring, is that no Civ feels 'special' by then as 95% of unique stuff has been used already. Sure, later UA/UU/UB should be more powerful than early ones, but so what?
Makes for an interesting "come back from behind" game.
I think I follow you on that gameplay model - I especially like the idea of an American carrier UU - but I think people have shorter attention spans so they need something to bite their teeth into right away, whether it be unit-, building-, or ability-related.

happiness. Cargo Ships can establish trade routes 40% further away
and 2
gold when pillaging improvements in Russian lands. Russian units can pillage their own improvements for 50 health. Workers spend no
movement cost for repairing improvements.
Production cost of 25 instead of 75 (Standard game pace), 25% decreased tile
culture &