People move around, including doctors. Even knowing what doesn't work can help future patients.

For an example, most of urgent medicine (e.g. battlefields) in history was built on this sort of chaotic progress, and not on meticulous scientific research.

It's not progress if it's just exploiting something people associate with high-tech medical magic, but that isn't contributing to the literature or sum of human knowledge, merely to the bank-accounts of the cowboys running the show.

Why are you so keen to attribute scientific breakthroughs to ... well to quacks? On the one hand we have bona-fide research by people understanding the science, using animal models to test and understand, building up sound scientific basis for treatment etc, and on the other we have people injecting god knows what into anyone with enough money, some of it human-origin, some of it not, very unlikely to be contributing to any corpus of knowledge, all because rubes heard "stem cells" on the news and think they're magic.

These are not serious doctors working on breakthroughs by disregarding the stuffy old rules that hold them back (though that's certainly one way they like to sell themselves), they're quacks selling bullshit and scamming people.

I would argue it’s only cowboys participating because the FDA has effectively told everybody the only way to play by the rules is by spending large sums of time and money which gate-keeps new entrants and stifles progress and contribution to the sum of human knowledge.

The bar can be lowered without allowing snake oil and holding snake oil salesman accountable, granted this is much harder to do when people travel internationally. At that point, the consumer owns the risk they are taking, regardless of how precarious the situation is.

This is an over-regulated industry that has been captured by existing entities who would rather pay the exorbitant fees for incredible returns than allow new entrants to the market.

That's really orthoganal to the question of "are stem cell clinics in Mexico a scam?"

Is there too much regulation in medicine? Could be. There's certainly regulatory capture evident in many parts of many economies.

You say orthogonal, I say it makes the question moot by solving the issue upstream from the “need” for suspicious and unregulated medical treatments.

I don't think it would - if the treatment has both been hyped in the press as a potential panacea, and yet is not at a stage of development where any honest practitioner would offer it, there is still a gap where the cowboys will jump in and sell to the desperate.