The Kids in the Hall have come back together in order to make comedy. There does not have to be any other reason than that for them to entertain people and remind everyone just how good they were back in the 1990s. Every lame comedy troupe since then owes the kids everything.
As for how they have aged, come on, man. None of us are aging well. We need chemicals and implants to survive in these harsh times. Let it go.