@jerodleupold GM-less-ly? (Which would be ideal, given the trip from Microscope and Quiet Year...)
The obvious place to start might be #Kingdom (https://www.lamemage.com/kingdom/). Certainly Diplomacy falls out extremely well on that one but Horror is shockingly doable. Escort and Heist, not so much.
However, since we're still doing Ben Robbins games, #Follow (https://www.lamemage.com/follow/) is _fantastic_ and too often flies under the radar. It's a great game and the core mechanics are available for free with several Quests, Get the whole thing; you'll love it. Here's your Heists and Escorts, straight-up.
There's not much I _won't_ recommend #Starforged (https://tomkinpress.com/products/ironsworn-starforged-deluxe-edition-rulebook) for. It does pretty much everything you could need but it definitely requires a certain fiction-first mindset that can challenge some. (Yes, you can do a straight up modern game with Starforged; if your setting is fantasy, there's #Ironsworn .)
If I'm going to pull one game out with a traditional GM/player dichotomy (though -- not quite), it'll have to be #Wushu (https://danielbayn.com/wushu/). Deeply unconstrained, rules light, and infinitely flexible. It's as grounded as you and your fellow players want.