My experience of the wargaming community is that it can be largely divided into figures gamers and board wargamers, and the overlap is limited. The board wargamers are used to counters, hexes and stacking; the figures gamers are used to arrays of painted metal soldiers on a baize cloth, rulers, and no stacking. Civ 6 is an odd sort of hybrid, in that the units resemble figures, and don't stack, but move on a hexgrid map. Also, the scales are different - figures gamers may play out a Napoleonic battle, but not an entire war or even campaign. If you try and work out the range of a crossbow in km in Civ 6, the answer is absurd, but that doesn't matter because it is a board game rather than a wargame.
The problem with the unit graphics in Civ 6, apparent in the first screenshots as Krajzen says, is that they are just so much worse than those in Civ 5. A spearman unit in Civ 5 has eight wee men and looks like a reasonable representation of a military unit. The same in Civ 6 has only four men, and looks like four pals out for a stroll. And the "ironclad" in Civ 6 is a riverine gunboat that could never operate at sea.
No telling what Civ 7 will look like.
Board games and miniatures games (metal figures on a baize cloth) have one overwhelming difference between them, and it relates to their comparison to computer games.
Miniatures is all about the aesthetics of the game as much as the playing of it. That is, the gamers want their armies to Look Good, they want the spectacle as much as the victory. The period of the late 18th - early 19th century, when military uniforms reached their peak of sartorial splendor (the Napoleonic Wars) has been perennially popular among miniatures players for just that reason (although WWII, with all the varied tanks and equipment resplendent with camouflage painting, slogans on the turrets, etc. is also an extremely popular period for miniatures gamers).
Board games, not so much. In fact, Redmond Symonsen, the graphics designer for the old Simulations Publications (
Panzerblitz, Strategic & Tactics magazine) used to do periodic rants about how bad board game graphics were in general. In general, board games have concentrated on making the game's required information as accessible as possible, avoid turning the gamer's stomach with their color choices, and pretty much stopped there.
Other than that, the fact that 99.99% of all miniatures games are strictly about the battlefield and its events and ignore (or nearly ignore) operational or strategic moves completely, while most board games are strategic, grand strategic (like the ancestral
Diplomacy or
Civilization boardgames of 30+ years ago) or operational in their focus, is a relatively minor point: as it happens, the 4x category, like it or not, is now forced to cover both to some degree: strategy and grand strategy because that is the actual focus of any 200 to 6000 year-spanning game, and tactical because gamers like to watch their little digital armies scamper around and 'role play' (pretend) that they are Alexander the Great, even though most of them are closer to Jubilation T. Cornpone in their tactical acumen.
But it means that describing Civ VI as a 'boardgame in a computer' is not precisely accurate, or more precisely, it illustrates the basic flaw in that concept: computer games are also, both as playable games and as commercial ventures, All About Aesthetics as well. There's a reason why a large percentage of the driving force behind constant upgrades to graphics cards and computing power in PCs is driven by Gaming, not productivity: gamers want games that Look Good, and that means, any more, animated, detailed, and beautiful units (pixilated cardboard counters or static figures Will Not Do) and terrain to play over.
And, as stated, that is where Civ VI missed the mark: compared to other games like the latest
AoE,
Anno 1800, Humankind, even
Old World, the graphics simply look like they are a generation behind.
Of course, workable Game Mechanics that make for a playable and enjoyable game would also be nice, and Civ VI has managed to take every good idea it had in that area and bury them under piles of DLCs until the game has become nearly unplayable. I confess, I have
never played into the Information Era, because by the Atomic Era I am so bored and put off by the game that it becomes a chore to continue - and I have better things to do with my time than play a game that is a chore.