That otherworldly completion percentage has to be what has New England's attention. Both Tua and Jones put up huge numbers with similar supporting casts at Alabama, but 77.4% is the all-time NCAA record, bar none, and in the context of a national championship.
He may not have the highest ceiling in the draft, but that floor is pretty high. An elite decision maker with accuracy and even an average arm can put up 3500+ yards and 25+ touchdowns with low turnovers in New England, and that's coincidentally good enough to contend for Super Bowls with our coaching and defense.