I'm 70 and adapted. The MX 1000 was a great mouse but it was heavy and quite large. I find it a lot easier to use a smaller mouse these days. I got a Razor Deathadder Elite gaming mouse because I was wearing out so many smaller wireless mice gaming, but the Deathadder is slim and feels more like a mobile mouse to me.
I replaced mine with a Logitech Performance Mouse MX. Very similar later model. Drawback: It loses charge pretty quickly, but can be used as a corded mouse while recharging.
I'm happy with it.
I purchased the Logitec Performance Mouse MX, too, from a very well known supplier. Today I shipped it back. The "Zoom" button would not accept re-assignment. The "Application" button wouldn't work at all. And probably worst of all, the 3 pads on the underside of the mouse showed quit a bit of scratches from what I think was previous usage. So, now I'm expecting a refund.