Why? Because of big pharma?
People sacrifice their lives for their children, do you think the law will really restrict people from saving/improving their children's lives. You think the law would be enough to stop you from saving/improving your own life?
1. Insurance. As soon as it is cheaper to keep people young as compared to keep elder people healthy/alive, insurance companies will hand out these procedures like candy.
2. Medical tourism. IP is only valid within a certain jurisdiction. Reverse engineering a cocktail of molecules is not easy but well within reason. Manufacturering said molecules is ridiculously cheap. Even training professionals in other countries is relatively cheap.
3. Black market. If any white hat leaks these formulas or recreates them. If I chose to I can buy clean heroin from a reputable dealer online. You think I wont be able to get a life saving drug for the cost of manufacturing+tiny margin?
FWIW, this is already commonplace for a lot of poor people and their "restricted" access to expensive drugs.
Technology seems to imperil this age old truth. What about an immortal billionaire with drones, AI, and a robot army?
The coming elite will have power that no human individual, or even organization, has ever had. We should figure out how to deal with that - but I don't really expect the common folk will. Instead, we may just have to hope that our future billionaire deities are benevolent.
1) You give it to everyone.
2) You make it expensive, but not prohibitively. Maybe out of reach of the lower class, but obtainable to the middle.
The latter is more likely. Though if we're looking at the emerging markets with automation, we see that #1 isn't out of the question. If you're making money from people, the amount of people helps you make money.
In reality I think it'll take quite some time to get to either of those points. Because in the beginning this technology is likely to be extremely costly. And I worry that this fact (I'm predicting the common s-curve) will prevent it from becoming cheap.
There are people who'd like others to believe this. There is money to be made as long as people hope death can be avoided. What's the evidence that this will ever be true, that it's even possible?
I agree with you that a situation where a real life extension technology was available but costly—especially if it required tissue from young people—would be pretty terrible.
I hope we don't find a fix. The last thing this world needs are immortal god-barons running around extending their greedy agendas.