I've tried many types of remotes with my 80+ y/o parents, and all have failed. Old habits are nearly impossible for them to break. My incredibly simply touchscreen remotes end up collecting dust, and they always go back to juggling their old OEM remotes. And they don't have the dexterity or eyesight (my dad had only one good eye and zero depth perception) to operate even the simplest touch screen with gigantic buttons. Not to mention the additional requirement to keep the thing charged.

In my case, no solution exists besides printing out procedures for them to use with their OEM remotes and labeling them appropriately.

Good luck