Hey, Wikia has this relatively new thing called portable infoboxes. In the basic case they are easier to create than those old templates, and they work better on mobile, which is, I believe, a trending platform. So we've been meaning to create new infoboxes as portable ones. You should take a look at the syntax and everything before creating new old school templates for Civ6.
Also take a look at Template:Buildings_(Civ6) that this guy User:HyperdriveJ just created. It's completely made with the new syntax. A bit too many fields for my taste, but there might be some crucial ones that you may have missed.
I actually already knew of these, but I thought it was more this wikias style to use the old ones. I'll start shifting some of the infoboxes to this later, and make sure to use it for when I make new infoboxes. Thank you.
The majority of our infoboxes have been created before the portable infoboxes were introduced, so I can see why you'd think that. :) In an ideal world we'd convert the existing infoboxes into the portable format, but nobody has had the time nor drive to do that yet. Right now our priority is in everything related to Civ6 anyway. (But that shouldn't and doesn't prevent me or anyone else from editing stuff related to, say, Civ2, like when I recently did when I finally uploaded all the Civ2 unit images. The Template:Advance (Civ2) is also portable.).