I honestly think Jaylen Waddle will end up the best fantasy WR from this class. Its a good WR class though. Issue for me with Chase is he doesn't really create separation that well, he's a superb prospect otherwise.
If he wasn't at Philly, Smith would be for mine, personally reckon he's comfortably the best of the three, just a super refined route runner with excellent athletic ability on top, similar to Jefferson last year, that route running becomes incredibly important at NFL level and is what really separates guys unless you're a freak level athlete. Philly part though is a real value killer though.
Bateman might actually be the best as a rookie though, should get a lot of 1 on 1 matchups which he is very strong at.
Harris is a lock though as the best fantasy pick from this draft.