Ill say two things that may seem contradictory but they arent

1) You can google dozens of clips like this of Bradley doing an incredible job with on ball defense.

Bradley vs Steph Curry(2016 or 2017). Bradley vs Goran Dragic(late march this year). Bradley vs Kyrie Irving(many examples) Bradley vs John Wall(many instances that playoff series). Bradley vs Jimmy Butler(first round this year after game 2). List goes on and on.

All due respect to the many great defenders in the NBA....Bradley is in a league of his own when it comes to pure on ball defense on 1's and 2's in the NBA.

2) That said......all the evidence has shown Bos can live without him

a) 19-8 without him this eyar while hurt

b) Defensive rating has never suffered at all without him on the court(quite the contrary). All the theories weve had to blame his bad on/off defensive data dont hold up

We used to blame his bad rebounding.....well he made a giant improvement this year with that and still the data is teh same

His defensive rating with Isaiah Thomas on the court this year vs without him was almost identical.

c) He was due a massive pay day in 2018. Boston badly needed another 4(Jae Crowder cant be playing massive minutes all season at that).

If you can get back a solid option like Marcus Morris for him. Out of trading Marcus Smart(also 1 yr left wouldnt have fetched a ton) and Jae Crowder(great longer contract, much more size than Bradley more defensive versatility) Bradley was the best option here.