In 2020, Jones ended up with 4,500 yards passing on a 77.4% completion percentage, threw for 44 touchdowns, and had only 4 interceptions. He led Alabama to another National Championship under Nick Saban, so as far as production is concerned he has few equals.
His stats in terms of completion percentage and yards per attempt and overall rating align fairly closely with the last Alabama QB (Tua Tagovailoa) though one area where Tua is streaks ahead is across a similar number of games he threw for 87 TDs compared to 51 for Mac.

Jones has been extremely impressive this year. He’s making elite throws against good defenses. His footwork and throwing motion are great. His accuracy and deep ball are also excellent. However, his arm strength is only average, but it’s good enough to make tight-window throws, although he can struggle on deep outs.

His elite wide receivers and offensive line make it too easy for him. He throws with decent anticipation, but not the best, has a pretty deep ball and his footwork is a little suspect. When he sets his feet he can be excellent but often doesn't - resulting in some errant throws.
He also doesn't really read defenses very well. He's had several balls this year that should've been picked. His misdiagnosed coverages have got him into some trouble although this has been well hidden by having Devonta Smith and the rest of the Alabama offense to paper over the cracks

The biggest negative with Mac Jones is his lack of athletic ability. He is an average athlete at best and this will limit what you can do with him. He lacks the speed to be any type of a threat on quarterback-designed runs, or even when flushed out of the pocket. He doesn't exactly feel like a QB designed for the modern age.

There is nothing about Jones that screams elite prospect and it seems likely to us he has the talent to go in the second or third round, but in the right situation, he could be an effective but unspectacular signal-caller in the pros.
We think his ceiling is Kirk Cousins and his floor CJ Beathard.
The prospect of him being drafted at the top of the first round (going #3 to the 49ers) seems like a ridiculous reach, especially given there will be much better and rounded prospects available.