Should I try Civ VI or Humankind ? Has the latter been ironed out from its mildling release ? And is it indeed a Civ clone ? It looks sorta like a Civ mixed with a boardgame (the star thing is reminiscent of Scythe).
I would actually say Civ VI is closer to a board game - it's very streamlined, the differences between the civs are really minimal if you aren't doing early game PvP stuff with other humans, and almost every mechanic is pretty straightforward and easy to understand. The expansions kind of add a lot though, so getting the ultimate deluxe mega pack or whatever is recommended, and I'd even recommend modding after maybe your first game or two if you go with Civ, because frankly it still gets a lot of stuff "wrong" from a fun perspective.
I played Civ 5 and 6 enough to where I'm kind of done with them, and Humankind has replaced it. That said, Humankind feels like it needs about 2 or 3 major overhauls to different systems to be fully ready. It has received some big patches but I haven't played it since the first early bug fixes (kind of waiting for their next big patch, which sounds like it'll hit a lot). It DOES support modding using a 3rd party site, mod io, and has a ton of rebalancing etc. there. The main problems are the "endgame" kind of just... happens, once you get there you have probably already won and are just passing time, and some of the systems (pollution, the combat stats) are clearly and painfully flawed, but combat is functional, it's just kind of dumb (not that Civs combat isn't arguably worse).
Base game to base game with no mods.... honestly not sure, probably Humankind for me, as I think it has way more interesting things going on. Civ is has lots of expansions and mods and while Amplitude does have a good history of long term support, they don't always please everyone.