It's because they think that Russell will be a big player for them, but just like the rest of those who played with Lebron, maybe except Kyrie Irving, all of them turn into just another team mate and even if they are given a big role, I don't know they just succumb to the pressure I guess. Another great example is KCP or even Kyle Kuzma or THT, as far as I can remember there's a lot of hype surrounding this players, but when they played with Lebron, nah, all of them wilted under pressure that's why they are no longer with LA and then thrive outside.
Yup, all those names aside from Kyrie they all become nothing while playing with LeBron, so many promising opportunities, but it's management decision to keep LeBron and trade those known names after him, I guess only time will tell if what what Lakers management will do with those players that they still got playing with LeBron.
KCP becoming a champion with the Nuggets, helping them. While Kuzma had a so-so career with the Wizards, but there are games that he become the number one scorer. THT is with that Jazz, same, he gotten bigger physically, but he can still play. So we will see if Russell can break away from that shadow of playing with Lebron James and carving his own career now.
He can do it as he's welcome playing with that same squad where he really earn respect while playing for the Nets, though we don't know if what adjustment is needed to fit him but a as good player, it's mostly on you if how you adjust with the syste,.