Hakeem was better. He won a championship while surrounded by role players, and followed it up the next year with another title. He had a more versatile game, better stats, dominated in their H2H matchup in the playoffs, etc.
But, Robinson was a remarkable player, too. His stats are similar, and he was the same type of elite scorer/rebounder/defender. His team won 30 out of 42 regular season matchups against Hakeem. I think he unfairly gets knocked down for needing Duncan to win. That’s true if almost everyone, though, including Jordan, Russell, Lebron, etc. Hakeem winning without a great player beside him is a rarity in NBA history, not an expectation anybody should be held to.