

Splitting the game into distinct eras that atomically enforce switching is novel to me as someone who plays quite a few 4x games including humankind.
Enjoyment of a game is always going to be relative, this bitter hatred & entitlement at the pit of some gamers souls brings down the whole medium. You don’t like the game? Don’t play it, go on and enjoy the hundreds of thousands of other games out there rather than linger and whine until the devs cater to your whims.

For better or worse Ed Beach, designer of Civ VI, decided what makes the next iteration of Civilization Civilization. Like it or not, civ switching is now part of the franchise.
Maybe you should try Old World? That game is rad too.