Leo Messi was one of the greatest signing for Paris Saint-Germain but they've failed and missed out on golden opportunities, we just have to see the present scene of the system. PSG had everything to win major titles but they failed woefully because the management failed also, bringing them together to achieve a common goal straight out seems challenging. Real Madrid is executive the best team in the world of football and we unfortunately the principles they've been operating on. They will lift more elite titles infront.
Why do you consider Messi the best acquisition for PSG? Messi in PSG was remembered by the fact that he could not adapt to the team for a very long time, scored not many goals and received a huge salary. PSG is trying different tactics, they thought that they could collect all the best players in the same team and this would allow them to win, it is now clear that they abandoned this idea, and Enrique showed them that without all super players he almost reached the final, and if only a little more luck could have played in the finale, because PSG looked better than Dortmund.
Did Messi badly performed or was he the problem they never won as much title. Personally, Messi performance was outstanding and him alone can't give them those titles, you don't specifically point out one player out of the team as to why they failed to win trophies. Messi was as of much threat to opponents compared to anyone in the team, he did the best he could but seems the team as a whole were unable make better records as expected