Sostratus
Deity
Well, a few things:I'm on the team: "buff everyone, don't nerf". Nerfing often go with blandness, while buffing is often "adding some stuff on the top", the stuff added could be used to make something very interesting.
The devs we know of mostly play on prince/king. They aren’t MP meta gamers.
Balancing civilizations against each other isn’t the only concern. There’s a lot of other content in the game that things have to be balanced with, like how fast players get through the tree, systems like housing and trade routes, etc.
Moving the overall power level of all civs can mess up that balance with everything else and interfere with the original intended gameplay.
That doesn’t mean things cannot change, but its something devs need to watch out for over the long term.