How do you know they're not investing in it? If they are would it be worth their trying to make money on it or would they consider it worth more if they kept it to themselves?

You can't 1000x investment if there is no barrier to entry for competition.

They're saying a treatment that can actually reverse aging and prolong lifespan is worth 1000x more than money, especially to someone who already has more money than they can possibly spend in a (currently expected) lifetime.

There are other barriers than patents. First mover advantage, brand name recognition, first to achieve low cost, strategic partnerships, etc.