Barcelona against PSG in the first leg pulled out a perfect offside trap for a set piece leaving all the PSG players offside. Although a very effective tactic,if the element of surprise is removed then it becomes very risky. Barcelona probably aren’t going to try this out again this season as opposition teams now will be wary of this tactic. All it would take for a opposition player to make a run from deep or the free kick taker to be a dummy to ruin this tactic. Also you are dependent on the linesman to give the correct decision which in this situation was quite easy for the linesman.
Basel tried it out against Schalke in the 2013 Champions League only for the linesman to make an epic blunder and not spot the offside.
So when such crucial decisions go against you,teams generally are very averse to taking such a risk. Luis Enrique took a chance and it came off perfectly. Enrique except for the Messi issue which nobody really knows what happened has been his own man refusing to bow to pressure from either the fans or the board. From moving Messi out wide to dropping Xavi completely from the big games,Enrique has taken some tough decisions which have payed off well so far for Barcelona.