Bagpuss
Legend
Birthright would absolutely work in the modern day.
The devil of it is... there's nothing -special- about it.
Going to have to disagree.
Like yeah, playing a ruler is cool, fighting wars is fun, but you can do that in literally any campaign setting. And often do in Dragonlance and Forgotten Realms. Eberron is everything Birthright is, plus -other- stuff.
I can't think of any other campaign setting where level 1 you start as ruling a kingdom. I mean you could do that in any campaign setting, but none of the rules or structure of the settings really support that. Cerilia is fractured into lots of small nations making politics an essential part of the setting much more so than any other settings you mention. The domain system is set up to support ruling a kingdom unlike every other setting. But not only are the countries fractured but the religions are as well, so you have multiple religions that worship the same god, but don't get along, adding a whole other level to the politics.
Then you have unique a halfling race that can step into the Shadow World, elves that hate humans with a passion, the whole bloodline mechanic, and blood theft. Also you have the issue with magic being attached to the natural state of the land, so the more developed a region is the less magical it is, the Battle Magic mechanics. The fact that the key monsters are unique, you don't have a load of Gorgons, you have The Gorgon.
There are loads of things special about it.
Best of all NO GNOMES, that alone is a huge selling point.