My personal opinion?
It looks cheap and trashy. Like a free mobile game. Clash of clans isn't far from the mark. Terribly unrealistic and thus anti-immersive. Yes the resolutions will improve etc - but I hate this art style.
To me it looks designed for consoles and tablets, and is made to appeal to the widest possible audience (obviously - as any series of games does these days which is why us old time gamers get so annoyed by them because the gritty, darker games we used to play in the 90s are things of the past) so it's for kids, millennials, MOBA fans etc.
That's what all big games do nowadays. They take a great product and try and turn it into a cash cow by appealing to a wider audience than the people who made it popular in the first place - and the hardcore fans hate it as a result. Same thing happened with the total war series after Sega bought it years ago. I used to adore the original medieval total war and the first shogun (1 - not 2) - it went all mainstream and as a result - made a lot of money, but I lost my love for it.
With civ - I loved civ and civ 2. Hated the cartooniness of 3 and 4 - loved (and will continue to love 5 after the mechanics became much more fun with the expansions) and look like I will hate 6. From what I've read don't think I'll be buying.