Perhaps it goes beyond the brightest minds at Google that people can grasp things with their eyes closed. That we don't need to see to grasp. But designing good robots with tactile sensors is too much for our top researchers.
All the best ideas are tried repeatedly until the input technologies are ripe enough.
But perhaps a great benefit of tactile input is its simplicity. Instead of processing thousands of pixels, which are passive to interference from changing light conditions, one only has to process perhaps a few dozen tactile inputs.
Ex-Googler so maybe I'm just spoiled by access to non-public information?
But I'm fairly sure there's plenty of public material of Google robots gripping.
Is it a play on words?
Like, "we don't need to see to grasp", but obviously that isn't what you meant. We just don't need to if we saw it previously, and it hadn't moved.
EDIT: It does look like the video demonstrates this, including why you can't forgo vision (changing conditions, see 1m02s https://youtu.be/4MvGnmmP3c0?t=62)
Those are realistically the 'natural' developments in the domain knowledge of Robotics/Computer Science.
However, what GP (I think) is raising is the blind spot that robotics currently has on proprioception and tactile sensing at the end-effector as well as a along the kinematic chain.
As in you can accomplish this with just kinematic position and force feedback and Visual servoing. But if you think of any dexterous primate they will handle an object and perceive texture, compliance, brittleness etc in a much richer way then any state-of-the art robotic end-effector.
Unless you devote significant research to creating miniaturized sensors that give a robot an approximation of the information rich sources in human skin, connective tissue, muscle, joints (tactil sensors, tensile sensor, vibration sensors, Force sensors) that blind spot remains.
For the inverse of the robot problem: younger me, spoiled by youth and thinking multitouch was the beginning of a drumbeat of steady revolution, distinctly thought we were a year or two out from having haptics that could "fake" the sensation of feeling a material.
I swear there was stuff to back this up...but I was probably just on a diet of unquestioning, and projecting, Apple blogs when the taptic engine was released, and they probably shared one-off research videos.
Blind people can grasp.
Stretch goal: small kids can walk on their hands.
Sorry, but I just burst out laughing at my own comment, when I considered the technical difficulties in trying to teach a robot to handle the change of context needed to balance on its hands, rather than its feet, let alone walk around on them. Ahaha.