Lee's a decent player but it's hard to argue that he's a huge upgrade over Bradley, particularly given his age and where we are with rebuilding.
And like others have said, there's no reason to extrapolate from his early season numbers this year when we have eight years of history suggesting that, you know, he probably won't have a 70% TS% for the season.
In fact for those who've been arguing that Bradley could never be a starter on a contending team, Lee might be the best counter-argument you could find right now. There are more similarities than differences between the two.