After the Lakers were booted from the playoffs by a younger and faster Thunder team, Luka Doncic reminisced about what could’ve been.  In March, the Big Three were healthy. They had gone on a 15-2 run. They were soaring .  “We thought we were gonna compete for a championship,” Doncic said. But those hopes dimmed amid a string of injuries to Doncic (hamstring) and Reaves (oblique), and ultimately came crashing down against a second-round opponent that was deeper and vastly superior on both ends of the court.  LeBron James was the only one of the Lakers’ Big Three to be healthy for every playoff game.…