I am not so certain I agree with you on Mays passing. His only significant playing time came in 2017-18:
In the air:
8 Games, 75 of 113 passing for 905 yards. 113.1 per game and a rating of 143.6 with 4-INT's. 4TDs
With his feet:
Averaged 9.1 rushes per game, for 75-yards. Also had 4TD's and 2 fumbles.
He had 3 times as many yards passing, as he did running. Actually it was a less than balanced attack that favored the pass, in which Mays was highly efficient.
It is really the matter of making a commitment to using Mays, and opening up the play book. To me there is not doubt that VG has grown and can throw deeper/tighter patterns into traffic, but Mays offers quite a bit of unique skills himself. How far would Mays have advanced this year ...I do not know... but I still think he demonstrated last year that he can lead this team.
Where VG has the distinct advantage is keeping the pass-play alive (with his feet) after the snap, and this is where our line is failing.