Unironically, the side that is more often correct in a given debate usually has way better memes. It's a decent (albeit not foolproof) heuristic. And it applies to humor more broadly, with memes basically being the haiku form of humor.

-When you find something funny, it's often because you subconsciously agree with it, at least partially. Sometimes you're trained that you *should* agree with a given side, but humor just cuts through it and reveals that really you kind of don't, and in some way forces you into an honest moment.

-Creating a meme requires condensing an argument into a short context. While outright lies are easy to make short (i.e. you can just say a false thing that requires the other side to take time to unpack), actual arguments are not so easy to make short, especially if they're also going to be funny. A meme that has any sort of point to it generally has an argument embedded within it, even if that argument takes the form of an observation or other simple thing. Outside of highly technical contexts, arguments/observations are generally easier to condense if they're true.

The side of a given debate that reliably can make short, funny arguments is typically on to something.