Because there's no guarantee those teams will have a HC, OC, or weapons when he gets there. Those teams have provided evidence they're willing to surround a QB with weapons when their QB doesn't get paid anything. What happens when the QB is making $50M?
In two years, there's no cap gymnastics possible where Lamar, Tyreek Hill, and Jaylen Waddle are on the same roster. One of those three guys won't be there.
End of day, when Lamar's getting paid market value, he's not going to get a bunch of high end weapons. If he gets 1 or 2, that's a ton, and one of them will certainly be on a rookie contract. He's going to have to elevate his players, not the other way around. That'll be true in Baltimore or any other franchise.