I know everyone hates the analogies but WNBA has been around for a very long time. Girls have been playing basketball for a very long time. Their skill level is maxed out and still the sport struggles. WMMA will exist because men's MMA exists. Take away men's MMA and you get Invicta, if Invicta qualifies as a successful endeavor in any meaningful sense well then great. Doesn't mean from time to time a female fighter or three won't capture the public's attention en masse. Athletic ability isn't incredible enough across the landscape of WMMA for it ever to gain widespread appeal. Women's tennis is on the opposite end of that spectrum, but you know who plays tennis in addition to men? Women, in largish numbers, so they have a legit world wide fan base consisting of men and large numbers of women. Most women aren't looking to get punched in the face or grapple. Most women hate, strongly dislike, or never give a thought to MMA.