D&D-like games set in an historically accurate 16th century are rare to non-existant. People might think of D&D as set in the past because of the assumed technology level, but we don't have to assume that history and social and family structures mirror our world at the time.That is my point. But most RPGs like D&D are set in a world roughly 500 years ago.
In D&D fantasy worlds, we have what we decide to have in them. I can imagine a Rome-like dwarven empire that abhors slavery (an abomination in the eyes of the Merchant Gods) or a Viking civilization that defends coastal settlements from squid-folk incursions rather than plundering those coastal settlements.Some trappings require bad things though. You can hardly have Rome without slaves or vikings/pirates without plundering.
We bring in a lot of baggage (sometimes intentionally, sometime unthinkingly) when we import trappings into a fictional fantasy world. The intent I think is to evoke a sense of the world, but doing that without analysis and intention can lead to some cringe-worthy worldbuilding. I'm not being judgemental here. I'm as guilty as anyone -- well, guilty isn't the right word. It's not a crime. Let's say that I've done it -- I've tossed in a pastiche of tropes into game settings without really thinking about whether it's what I really meant to include.
Justifying the inclusion of a particular aspect of the real-world past into a fantasy or alternate history setting solely on the grounds that such a thing exists/existed in our history is a bit lazy (which I am sometimes) or perhaps a difficult-to-avoid shortcut.
I have a high regard for folks who can research and set games in an historically accurate past. I don't think I'd want to play in those games, but I admire the ability to evoke that past.