I am a little more positive about that Aubameyang transfer to Chelsea than you. First of all i think it was a good deal for all three parties involved because first of all FC Barcelona is broke and needs every € of transfer fees that they can get and also every € that they can save on player salaries. Then of course it is also good for Aubameyang because i would guess it always sucks for player to play for a club that wanted to get rid of you. FC Chelsea was desperately looking for a striker and i think for that price tab Aubameyang was a great buy. He is still very fast even though he is 33 years old already and if he feels good i am sure he can still be a efficient striker.
I am still doubting the ability of Aubameyang to change the goal-scoring challenge of Chelsea. Chelsea still needs another younger goal-scorer to back up the effort of the former Gabonese international. But, I think his transfer would be a plus to the Chelsea team in terms of experience and mentorship. Younger Chelsea strikers would be able to learn certain outstanding qualities of a good striker from him. Chelsea is now scrabbling for players while they had all the time to buy quality strikers. Good luck to Aubameyang and I pray he replicates the impact of Benzema and Lewandoski in the EPL.