To be clear, the kid is a special talent. Like elite talent. He's not an elite player yet, but he could be a world class striker. No exaggeration. Mbappe is obviously better, but even he's 20 and will turn 21 before Kean even turns 20. Kean is REALLY young, but has played minutes in Serie A for both Juventus and Verona.
I think a guy like Rafael Leao, who is the other young talent we've been linked to is really talented, but he's older than Kean and hasn't quite been as productive, either. They are comparable, but think Kean is the brighter talent. Put it this way - I think Kean is better equipped to come in and play right away than Leao.
Or you go with Goat's boy, Seb Haller and hope he can adapt to the PL quickly.