I think it’s a refutation of unregulated production & resource distribution in general.
In socialism, distribution would be handled by the state or locality, by the producers themselves, by a work coupon system, with money (a la market socialism), or theoretically in a sort of free-for-all all where people just request what they need. Only the last one is really implicated in a tragedy of the commons type scenario, with the money and work coupon systems potentially causing a smaller degree of that sort of an issue (as there would be less inequality, so less possibility of overproduction due to demand). Producers would, in that case, be encouraged to produce more to fill the increased demand, but there wouldn’t be a profit motive for doing so, and so a consumer-side tragedy of the commons is less likely. Also, producers’ access to resources would theoretically be more tightly regulated than in capitalism, but that isn’t necessarily the case.
In capitalism, distribution is dictated by the money system obviously and due the massive inequality there is a big disparity among people’s buying power - but more importantly companies consume the vast majority of resources and are encouraged to grow infinitely in a world of finite resources - creating demand where it doesn’t naturally exist to squeeze more profit out of folks’ savings, make them take on debt, or cause them to deprioritize other purchases.
In capitalism, people are not encouraged to consume infinitely more because it is not possible. You only have so many needs and so much income as an individual. The market invents new needs with advertising and such (you need makeup, you need the newest smartphone with ten cameras, you need glasses that let facebook spy on you), but consumers’ buying power is limited. People can’t really cause a market-wide tragedy of the commons, only companies can because they have the vast majority of the access to resources and the ability and motive (profit motive) to acquire them.
Tragedy of the commons, or some iteration of it, seems inevitable under capitalism, but is mitigated or eliminated under socialism
Idk about MMA, but afaik his kickboxing record was pretty good, but essentially he was an average/slightly above average pro who had a massively padded record - he mainly fought people who were ranked far lower than him, won some low to mid level titles and didn’t take actual fair matchups or compete in tournaments that you’d expect actual highly ranked pros would compete in.
So, he was a perfectly adequate kickboxer (I am certain he could kickbox better than me: a marginally athletic casual BJJ practitioner who does not know how to kick things) and even a lot of pro kickboxers in lower divisions but nowhere near “best in the world” / “olympic level” or whatever else he claims