The risk of Lewandowski playing below expectations in my opinion is small, yes there is a possibility, I can't deny that. But if a player has very high ambitions for one club, he definitely gives everything he can. Because if you see Lewandowski's desire to join Barcelona, it is very passionate. That's a plus for him in my opinion.
I think the odds are still 50:50 between done deal or not. Barcelona may start to turn their attention to other players and Raphinha who is currently still one of the Leeds United players. The situation of Barcelona and Lewandowski only really depends on Barcelona's financial condition and also the considerations of Bayern Munich. If Bayern Munich agrees with Barcelona's offer then maybe this transfer is now a deal, but so far progress has been very slow.