I do agree that he didn't perform well last 2 games. But couple of factors to keep in mind: (1) DJ Chark was injured and just came back 2 weeks ago; (2) defenses stacked the box against Minshew; (3) CT was not on the covid list.
If you look at his usage this past weekend against LAC, Robinson was literally on most if not all of the snaps, basically assuming CT's 3rd down role. Chargers didn't stack the boxes at much which gave Robison more running lanes. But even other teams do stack the boxes, as long as CT is out and Robinson gets 3rd down and used in 2 minute drills, he definitely has the skills to be in the RB1 tier (can't forget garbage time points) Once DJ Chark gets his groove back and the offense develops a solidified identity, I see tons of value for our boy Robinson.