I think that's a Facebook targeting problem, not a problem with the people buying the ads.
Somehow Facebook has no idea where I am, and I get local ads for all kinds for businesses in random cities to which I've never been.
There's also the concept of extended targeting. For example, as an advertiser, you run Los Angeles ads in Palm Springs because there's a lot of people who live in or frequently visit Palm Springs who also have homes/businesses in Los Angeles. Ditto to LA-Las Vegas, SFO-Reno, Chicagoland-Wisconsin, Minneapolis-Southern Manitoba/Western Ontario, Houston-Austin, San Antonio-Padre, Cincinnati-Carolinas, etc...
Of course, there may be controls the user has when creating ads that may've been messed up, I'm not sure, but I honestly only recall a few ads that were in my area so that I could, if inclined, act on them. The vast majority? The only way it would work is if they sold me on their platform so hard that I sold my house and bought into their district in their state.
Why,? The world would be a better place with less pointless political advertising
If we want to get special interests out of everything like we claim, then we need to have the platforms for people to get themselves out there to be both effective and cheap enough to do so.
Who gets to define "pointless?"
More specifically, the filtering would be informed by the biases and prejudices of those who control the gates. As it always is.