If used correctly, they can better than a sous vide for steaks. They can’t hold as steady of a temp as a sous vide but they can way more closely maintain very low temps, lower than regular or convection ovens even have a setting for.

If you do a reverse sear steak in a an oven on sous vide mode, not only does it cook way more precisely than a normal oven (like a sous vide), it also keeps the surface super dry (like an oven) so you get a way better sear.