Summary
Despite being a lottery pick in the 2018 draft, Robinson has been unable to make an impact in the league. The team option on the fourth year of his rookie contract was declined, and Robinson was waived by the Wizards this season. Robinson made a late rise up draft boards in 2018, mainly due to his perceived upside as a shooter. However, Robinson has been unable to hit shots at even an average rate, as he's hit 28% of his threes over the course of his three-year career, and has been near the bottom of the league in overall eFG%. He's also slightly small for a wing, which makes it easier for him to get shots off over the contesting defender, and makes it harder for him to compete defensively on the wing.

Robinson has had some moments of productivity, especially in the '19-'20 season when the Wizards short-handed, but those situations can be hard to evaluate, and weren't enough to outweigh the overall amount of evidence that Robinson has shown he just isn't quite an NBA player. Teams may still give Robinson a flyer but I would be surprised if he even got a fully-guaranteed minimum contract.
 
Cap Considerations
Robinson was waived by the Wizards this season, and has yet to be signed by an NBA team. Teams will have multiple ways to sign Robinson as even teams without cap space could possibly use any of the Non-Taxpayer MLE, Taxpayer MLE, or possibly even the Room MLE or Bi-Annual Exception to sign him. It's also likely that Robinson could be signed for the minimum.