Steering wheel rubber buttons sticky

try cleaning it....use a gentle cleaner, car liquid wax, or leather cleaner

 

It's rubber.
I occasionally wipe mine with Meguiars Interior Detailer Cleaner.

You don't want to use anything that would potentially contaminate the rubber or cause it to dry out.

I actually don't like that Toyota used "rubber" buttons. Regarless of what we do, someday they will deteriorate.
Our own hands and the oils and dirt on them will make it ultimately inevitable.

 

I have the problem... but nothing I've tried seems to help. I'm very interested if you find a reasonable solution.
The other issue is the silver wears off the steering wheel switch pad.