I'm still happily playing Civilization 5: With the Vox Populi Mod (which you can find here if your interested):
New Version: 4.15.2 (August 7, 2024)
Its still the best version of civ for me. Its so much more meaty, more balanced, the AI is 1000% stronger, and its constantly updated by the community (with a congress system to propose changes, you can literally impact the mod if you want to join!) I just can't get into newer civs nowadays.
I will give 7 a look of course, but I doubt I could really play it without the normal years of DLC they need to actually put in the needed content and polish, and even then it will be questionable. Its hard for me to play newer civs because the AI is so much weaker than what I have in Civ 5 VP
All of that said.... they HAVE to continue to innovate civ, and so I feel like people get way too down on changes because its new and different than previous games. That is what you want in a new title, I don't want EA's Madden 94, 95, 96 which is basically the same game with updated rosters. I already have Civ 4, 5, and 6.... I can play those anytime I want. 7 needs to stand on its own due to new unique mechanics and gameplay styles, not just "6 with better graphics".
The era system looks interesting. Mechanically the game has always had a problem that when you take a snowball model and try to stretch it over 400 ish turns, things get a bit wonky. The idea that they can package certain civs or themes or mechanics into a tighter time opens up a huge design space for interesting and balanced design. But I can also respect the idea that not getting to play certain civs until later in the game could be a thorn for some people, especially the modern era ones. We will see, but I get tired of the "oh god they changed civ, game over man"... what would kill civ is if 7 comes out and my reaction is "um ... its just 6 all over again"