Or because .. he has eyes?
Thiago is a magical footballer. He's not a directly creative player, he dictates play. You don't judge him off g/a anymore than you would Luka Modric. Technically he is absolutely sublime, almost entirely pointless pressing him, but he's an incredibly intelligent footballer too. He was one of the best midfielders by far in the Premier League this season, and was one of Bayern's standout players.
Of course he's better than Bentancur. Nobody outside of a Spurs forum would say anything different.