And Davis will be like 30 and may very well be the best player in the world.
Davis is not nearly the best player in the world right now, and I would be surprised if he is in that conversation 3 years from now.
I'm not sure any player could really be in that discussion in today's league unless they have the ability to handle the ball at the point of attack and create a high volume of three pointers, either by driving the ball and kicking to open teammates or pulling up from deep. I don't think Davis is that kind of player.
To be fair he can polish his passing, finishing and shooting to the point that he'd be the perfect big man in the PnR/PnP with a strong post game to generate his own offence if needed, and improve his defence to top of the pack rim protector levels. The offence of Garnett plus the defence of David Robinson is certainly a contender for the best player in the league (ntm a top 15 peak ever!).
I'm not saying that he will do all of this, but there's a path for him to be the best player in the league.
Honestly, in today's league, I'm just not sure a big man like a Garnett or a Robinson could be the clear cut best player. The league is so skewed toward creating three point shots, and the best players at doing that are guys who can both pull up and drive.
When it comes to late game situations, defenses tend to be really good at making it hard for big men to get the ball. Unless you can catch the ball behind the arc and work your way to your preferred spot, it's hard to be "the man." We've seen that with Joel Embiid.
It's looking like we're entering the era of Giannis and Luka.