I've had my ebike for about 4 years now. They have nothing to do with aging although I'm sure they could help older people. The main purpose is that you can travel as fast (or faster) as you could when exerting max effort recreationally but without getting sweaty if you don't want to. Normally if you're going some place of any distance beyond a few km you either have to wear athletic clothes and change once you get there or drive slowly so you don't get too sweaty. Or of course you could drive quickly wearing your normal clothes, arrive hot and sweaty, and have to go into the washroom and try to wipe all the sweat off with paper towels. Kind of negates the time benefit of going faster when you're in a hurry.
You can also wear fully water proof rain clothes in warmer months without getting sweaty and carry more stuff without the weight and aerodynamics slowing you down much.
It's basically like an electric car except you're still getting some exercise rather than just sitting there (similar to a brisk walk) but with almost none of the cost and the ability to bypass traffic during peak periods. I don't know about in other places, but here my ebike is faster than a car at peak periods except in outer suburban areas, and is often equally fast or faster off peak.
It would make a lot more sense to say that using a car instead of an ebike is a sign of aging (or general softness) if you don't need to carry passengers or a lot of cargo.