He's such a talented footy player.
I disagree he is not dynamic enough to be a fullback, he has plenty of toe and an ability to beat a player. Looking at other current full-backs, plenty go alright and are not what you would class as dynamic - Teddy, Turbo, Mitchell, Edwards etc
He is just a solid smart and skilful footy player.
In saying that, I think we forgot how important having Turbo in the backline is. When he clicks, he finds himself all over the park barking orders. He reads the game so well, and by injecting himself into the backline on both sides, he acts like a second 5/8. The opposition gets put in two minds and Tom is then able to create chances and put his centre or winger into space.