I think that the Aubameyang deal is beneficial for each side. Because Chelsea immediately needed to sign a striker before the end of the window. Otherwise a very tough season was waiting for them due to scoring problems. Aubameyang is one of the great choices available in the market. He is very familiar with the Premier League too so there wouldn't be any adaptation issue as well. Barcelona needed to get rid of some players to solve their registration problems in the La Liga also. Depay or Aubameyang was needed to leave and they reached their goal.