If you think Civ Swichting is the best and only way to fix the boring mid/ end games, great for you. I (and a lot of other participants in this thread) think however, there would have been a more practical and immersive way to do this. Plenty of alternative solutions (from levelling up your existing civ to having the leaders change instead of the civs) have been discussed in this thread already. Agree to disagree. No need to belittle people, who just do not share your opinion on this.
Alternative solutions have been discussed, yes, but they are offered from a single perspective, that of maintaining immersion via playing a single civilization through the entire game.
If that is the most important thing for you that's fine. Your perspective and disappointment in the direction Civ7 is taking are totally valid.
However, I stand by my comments that it is a narrow interpretation what roleplaying in the civ series is, and that it elevates roleplay over gameplay. Ages and Civ Switching (the two mechanics are inextricably intertwined, imo) are explicitly intended to address
gameplay, or mechanical problems. The devs have been really, really clear that they view the low percentage of finished games to be a problem, and they've publicly identified the latter half of the game as the culprit. Ages and Civ Switching are their solution, and they've also publicly stated reasons as to why they designed it they way they did - some of which directly and pre-emptively addressed some of the proposed alternatives in this thread.
Leader switching? Changing avatars would be confusing for players.
Keeping your existing civ? Not all civs existed at all times, so they decided to focus the designs around the period when that civ was at the height of its power, with all unique elements informed by historical research. No need to balance each civ to be strong at any given point in the game.
And you know what?
I don't know if it all will work. Actually, to be honest, I'm a little overwhelmed by how unique every civilization is - there's a lot to wrap my head around and when looking at the wall of uniques there's a risk that each civilization loses personality in favor of just being different combos of stat boosts. And I've always found immortal leader avatars to be silly. Heh - turns out narrative is important to me too. I've actually been finding it helpful to just look at Traditions for each civ to get a sense of its "personality".
But I do know that if a gameplay shakeup makes it fun to play a full game for me, then I can opt-in to the narrative framework. A different framework, sure, but a framework that's just as valid as the one presented in previous iterations.