I'd take Burrow cause he has a chance to be elite and Watson is just in the very good range.
But I would say in recent history that a lot of QB's have seemed to peak their first 2-3 years, seemed to have potential to trend towards elite and eventually fell back to the pack. Wentz was going to win MVP his 2nd yr before injury, Derek Carr was a top 3 MVP candidate his 3rd year before injury, Goff was lighting it up and went to the superbowl in his 3rd year, Lamar won MVP last year and was lighting it up.
A lot of potential regression as defenses get film on you, the team isn't as good when you get older, you get banged up a bit, lose guys in free agency, WR gets hurt, underrated pro bowl guard gets hurt, etc
Why elite QB is the most valuable commodity in the NFL, which obviously means.....Well, you know.