The same tech and AI that solves aging will solve many other things. Free electricity is coming "soon" from nuclear fusion. That will reduce the cost of everything else. We'll go from a scarcity mindset to one of abundance. More people will feel economically well off, and well off people have fewer children. But even if the population rises exponentially, space is limitless. The moon and Mars and space stations will be first but there's plenty of places that are/will be out there to explore and live.

Or something like that :P Stick around and we'll see what happens! Strap in, it's gonna be a wild ride. :D