I think it's the same issue, just shows up in different ways. Pre-mainstream MMA you had a lot of the mystical/flashier arts where people were trying to emulate stuff they saw in kung fu movies. Breaking boards, memorizing stances, punches and kicks with highly telegraphed movement, etc. People would get higher ranked belts in arts like these and feel confident despite a complete lack of pressure testing let alone sparring. These schools were a dime-a-dozen but honestly weren't worth much. I took Kung Fu for a few years as a kid and tbh I don't remember
any of it. Most of it was just stance memorization and the striking we did when we "sparred" was awful. Meanwhile, I've been taking boxing classes for a year now and I love that everything we learn is for the purpose of actual use in a match. The first class you're already learning every type of punch, and you'll be working on that along with your movement for as long as you train.
MMA is good b/c it filters out what works in martial arts and what doesn't. The prob is that "MMA" gets used as a buzzword and people want to learn it without understanding
why certain things work in combat sports and others don't. I feel like the average joe that wants to learn to defend themselves is better off just picking up something fundamentally strong like Boxing/Muay Thai/BJJ/Judo and grinding it out for a while. There's enough pressure testing going on that you'll get humbled and don't run the risk of thinking you're Batman after a few classes and getting whooped IRL.
And don't get me started on these self-defense "Krav Maga" McDojos that have people thinking they can take on attackers with knives/guns...