I don’t think it’s that women aren’t funny but that less women dedicate time to it or pursue careers in comedy. Think of the ratio of male to female comedians. Female comedians are pretty rare and humans instinctively make generalizations about rare things. This is usually referred to as a stereotype. Only a few funny women are needed to break that stereotype though.

But there’s also another aspect to it. People are unique in what they think is funny. I’ve seen clips of comedians that make the crowd laugh but I don’t think is funny. Some people like dark humor, some like over the top humor, some like offensive humor, and some like dorky fart noises 😂