Humor is a defense mechanism, a way for a biological bloodline to try to control destiny in the face of the uncontrollable. If you have money, if you have strength, if you have beauty, you have ways to attract attention and gain friends. Only when there is no avenue to get any positive attention do people try to entertain through humor. Because it's fucking hard, and there's no one size fits all. The effort that a comedian has to go through to trial and error jokes is humiliating. And, if someone already has a way to win attention, then that person won't get authentic feedback on if the jokes work or not.

Consider boss jokes. Some CEO who signs the paycheck throws out a pittiful attempt to be humorous. It's not funny, but are you going to not laugh? Likewise, some beautiful girl is interested in you and tries to make you laugh. It's not funny, but if she's putting out then sure, give your best laugh as payment.

That's why girls aren't funny. Not some biological barrier, at least not an authentic barrier. Just that girls don't have to be funny to get attention.