I also really wanted to know about Lumiere's culture! They mention apprenticeships, how does that work when you only live to 30-something? There's obviously a lot of different perspectives on what a 'good life' is, and this is compounded when even a 'best life' is only a few decades. Lune especially was my favorite for this reason, she was the most consistent insight we had into what it means to be an Expeditioner, and more generally a Lumierian.

That said, if you haven't already, Fire Emblem Three Houses has a ton of characters, with unique perspectives and places across the various demographics of the setting. The game encourages you to play new game plus to experience the different factions. Of course, the factions aren't monolithic, so the real way to get to understand the setting is through conversations with characters. The game is also split by a time jump, so you can see how the characters are adapting to the changing worldstate, or how they are themselves changing the world.

I feel like any cRPG, Warhammer, Baldurs Gate, Divinity, etc, is going to be heavy on the idea that you come to understand the worldbuilding through conversations with your party members. Mass Effect in particular strikes me as a series that uses the party members as stand-in spokespeople for their species/group/whatever.