As for maintenance, I never came across any gear problems in my whole 25+ years of driving various manual and automatic cars. And trust me, I've driven a lot and used a lot many of cars. So maintenance of auto tranny might be true of very rough or very old used cars but not for regular family cars.
Oh, I also remember, auto tranny cars were considered only for disable people back in 80's and 90's who couldn't change manual gears or clutch.