Davis seems to be very inconsistent in actually catching the ball. He has had Josh Allen his entire career and his catch percentage has never really been above 56%. Career average is 54.5%.
Samuel's career average is 65.4% catch percentage and has been upper 60's the last 3 years with not a lot of good QB's there in Washington.
And I think Mooney could do better with Williams than Fields.
I'll give you that Davis is bigger deep threat.
As anything, it will come down to how much a given guy costs.