I always liked history as a campaign setting, practically it saved me money and memory. One big advantage was it fed to each other, immersing in history and designing a game to make players feel as immersed as I am made me think really hard how to bridge the gap of Then and Now.
Historical Gaming is multi-disciplinary I had to study a lot more about economics and military theory, because sometimes sources are weak and it was better forensically teasing out information.
Because of how much research the average over-prepared GM compulsion would make, there were a lot of skills that developed from this hobby than from my Multi-Media Arts degree that allowed me to shift into analysis.
Everything I learned I had a chance to apply in a Historical Game, and because I was able to some-what practice so many skills in one activity it saved me time and energy and fed its own positive feedback loop. It was like taking up Acrobatics or Free-running, it was an exercise that exercised many stats at the same time, and in a way they had to work together for a sum greater than its parts.
GURPS is my go-to game for this, because its simulationist I can run it with other systems, going as far as Narrative Mechanic based system, depending on the audience and expectation. Although I have this in-mind for the Open RPG system project I am working on.
I decided to post pix of my books in hopes to run a history game either face to face or hangouts+roll20.
Historical Gaming is very niche as an RPG because for every book you read, it separates you from others who has not read it. It is an information barrier to entry, as well as playing the odds game of having someone who like RPGs and History. Of course, it becomes a barrier to entry if you make it a requirement to play a historical game, I usually "sell" the idea without emphasis of the history understanding doing everything to bridge the gap, so that hopefully players find it interesting.
There is a strong anti-science or anti-intellectualism movement happening around the world, and also my country. There are economic forces that actually influence people to take forgranted knowledge and population factor tends to grow the value. Sometimes it is a stigmatization to be in RPGs and History Nerd.