They certainly will be, but not necessarily for the worse. Imagine oil billionaires having to live through the consequences of their actions. Imagine the societal benefits of people being able to use their decades of valuable experience for much longer, rather than having it die with them.

I do believe it’s going to happen, but personally I’m more pessimistic than GP and don’t think it’ll be within my lifetime. Medical research is so tightly regulated when it comes to testing on humans (for good reason!), and there isn’t enough money going into the field.

That's one way to look at it.

Another is that this is the endgame for medicine as there is no other path forward. A huge amount of resources, both human and monetary, is spent to care for elderly people to slow the decline of their fragile health as much as possible — while still inevitably failing eventually. It's as if we've almost hit the ceiling of what can be done here with "traditional" methods. So it's the next logical step to declare aging itself a disease, because it's ultimately the cause of all those conditions, and start looking for the ways to reverse and/or prevent it.

I can say that about dozens of technologies that already exist, and several others besides a mere 18 year boost to average life expectancy that are actively being worked on.