The developers have heard the community's request.
In Sid Meier's Civilization 7, games are divided into several "Eras." During transitions between them, some parameters are reset (such as treaties), and the opportunity to choose a new civilization arises.
The authors wanted to encourage players to complete the game. However, reviews and online metrics (Civilization 6 outperforms the new installment) showed that franchise fans want to play as one civilization from the beginning to the end of the game.
Now Firaxis Games has confirmed that they are working on this feature:
We are internally testing ways to play as one civilization throughout all Eras, allowing you to choose a civilization from any Era and lead it throughout your journey through history.
