I'd suggest judges are the problem, not the media rankings.
Alex was in complete control of that fight from beginning to end.
Although Pereira's style doesn't win the judges over like Rountree's.
Rountree is this big, muscle bounded guy and when he goes in to punch he runs forward/jumps in with 2 or 3 massively loopy punches that look like they do a lot of damage. And when Alex defends, he stays in the pocket and rolls and slips with punches, so a lot of Rountree's big punches look like they're landing but they are just grazing him and doing no damage. Meanwhile Pereira's punches and kicks have no wind up. aren't big motions but they do a lot of damage. A jab or calf kick landing from Pereira was doing way more damage than those big hay maker looking punches from Rountree.
IMO Pereira looked safer throughout that fight than any of his last few.