Messi is in much better form than last season. And Messi's performance is good in every match.
He gets a better mentality in this season. In the past season, he just joined PSG in very last days before closing of a transfer market and he left Barcelona with big disappointment that all affected his performance. In this season, he did not have similar disappointment in summer preseason training and at beginning of season so he is more ready to play with his best.
Messi's role behind PSG's good performance in every match despite not scoring goals is undeniable. Messi is now PSG's playmaker. Messi strengthened the bond between PSG's midfield and forwards. And now we see Messi playing both midfielder and forward roles.
He is genius and we already saw it in Barcelona. Messi can play at all positions in an attacking system but in PSG, he has changed and played more regularly as a play maker as well as in midfield because he must has that adaption when he becomes older. He must avoid direct physical competitions with other players to avoid injuries and to prolong his career as longest as possible.
If Messi can continue this performance, the Argentina team can qualify for the finals in the World Cup. And can win against Bayern Munich in the Champions League as well. However, if Messi is not in form, PSG will not be able to win against Bayern Munich.
The World Cup will be the last tournament for Messi in Arghentina jersey. I think most of football fans will be happy to see Messi lifting the World Cup trophy in Quatar. He deserves to get it but in football, many great players did not achieve trophies they wanted.
Some legendary players even did not win Champions League in their career like Ronaldo Nazario de Lima (Brazil)