In a controlled environment - where the object to pick up, for example, is always in exactly the same location - you could do that. If there is any variation in the location of the object, you need vision to localize it each time. You need a camera, maybe two, and probably some kind of 3d perception, which is an unsolved problem at the moment (well, not solved in a general way, there are some solutions for specific objects).

Yes, they have systems to learn this way, but it assumes the environment is controlled (always) and the task identical (always).

Lots of automation works this way, but it actually limits the applications quite a bit.

A robot that can safely work along side people (i.e., a "cobot") and adjust to environment changes and changing work patterns is a whole different beast.