I have never had any issues with buttons wearing off in any of my cars, but I've been in several friends' and family cars that were worn out. The culprit is very easy to spot...if you eat in the car, have greasy fingers, use sanitary wipes (alcohol) to wipe down steering wheels, et al, and or your hands and then rub them all over your steering wheel or console, then ya, they will wear. I see it with my wife's cars. I told her to stop using them and since then (been a couple years) no issues.
If your hands are clean, zero concern. If you're a slob who eats in cars, have heavy fingers, and/or use hand wipes, then ya, buttons will wear.
Lots of worrying over nothing.