Somehow, I think we're missing the point and maybe braincells are being sent in the wrong direction. Well designed products don't need good customer support. My toaster works well. Haven't called them once.
If we are designing a thing is so terrible that it makes customer support necessary (other than the obvious corner cases that ai cannot solve) then sure, let a computer do it. We’ve already failed at every other step.
Your toaster is well... a toaster.
And even something as simple toaster might need some customer support. These things do fail quite often, sometimes dangerously.
Increase complexity even a little; or worse, deal with a service (phone, internet, subscriptions, etc) and you will need this safety net.
Nothing is 100% reliable in this world.