Yeah, population growth is a definitely another thing to consider. Earth is a closed system with a finite amount of resources. Natural resources would get depleted way more quicker in a world where reverse aging exists and there's a lack of population control at the same time.
In a world without age or health related death, society or what we have come to assume society ought to be like would have to be looked at in a completely new way. The absence of death challenges everything because so many things we do in our life we do at a certain time and age because biology dictates us to do so.
We'd still be linear beings because we only move forward in time but everything we have been taught or that has been indirectly taught to us about how to live our lives would have to be reconsidered.
Most of our current systems that keep our societies and economies working only work because people have an expiry date attached to them. Just imagine to literally having to work for the rest of your life or to 167 or 867 years instead of the 67 years you're currently expected to work (in Germany, at least) until you are put out to pasture. Or can there even be something like an retirement age in a society that doesn't age?
All right, we're already getting close to the point where 80-90% of the current jobs will be obsolete in no time because they can be just as well if not better done by machines. Who is going to support all these people? The 10-20% whose jobs couldn't been done without? Me do think so. Not.
To me there are two obvious solutions, A) everybody is given whatever they need to live their life in comfort. Period. And please don't ask where this support is coming from because that's the Pferdefuß of this plan. B) the productive few will be rewarded for their work but everybody else needs to figure out how best to survive with what they have or are capable of producing.
These are probably the two most radical options, there could also be a boom in VR technology and everybody will be happy to spend their life glued to their sofa, staring at the ceiling with their VR glasses on, consuming the bare minimum because your real life requirements don't matter anymore. Or maybe some smart cocky will come up with a plan for the kind of human augmentations that will allow us to replace 2/3 of our skin cells with tiny little solar panels that will enable our bodies to process sunlight for nourishment.
Governments of the world are likely going to take active measures to curtail population growth. This obviously raises ethical and moral questions. Procreation will either be heavily regulated in many parts of the world or even strictly forbidden. I expect people to revolt against this.
You're probably right in that the governments of the world will be quick to insist on population control - and not just population but a kind of thought control, too. Because in a society without drones, and in a society without death nobody wants to be a drone - not that they'd have to with 80-90% of the drone jobs being outsourced to robots - people will have a lot of free time on their hands. However, plenty of able bodies with plenty of idle time more often than not is a, let's just say, a rather unfortunate combination. So, for people not to run amuck, I'm sure our governments would see the need for lots of surveillance and a strict limitation of personal freedoms. But how long would a person / a world population with the potential to live forever put up with these kinds of restrictions?
There would probably be massive and bloody global uprising (because just because there is no need for you to die doesn't mean that your life can't be ended) and the ones who are left would have to radically adapt their view on how to live as individuals as well as an all but immortal world population.
Seems like there's a lack of practicality for reverse aging.
Not necessarily, but it would require a fundamental change in perspective in how we go about living our life.