PSG since being taken over by Naseer has spent a lot of money to fulfill its ambition in winning the Champions League trophy, but it is strange indeed when a team that is full of stars and able to dominate the league so far has only been able to reach the final round as their best achievement in the Champions League and even that only happens once, PSG has been building a team with a short time so indeed their team balance is often disturbed when there are players who leave and enter, we can see that so far PSG has often made player transfers every season and made the coach have to continue to change their main line-up which has the effect of team not being cohesive and not creating chemistry between players so far.
What you said is true, it is better for PSG to do what Manchester City is doing at the moment, it is better for PSG to start looking for young talents and form them into a unit in the team so that they have a very good cohesion like other teams, the arrival of Luis Enrique of course gives great expectations to PSG, Even though they failed this season, I think with his experience and ability to coach a team like Barcelona so far, of course it is possible for Enrique to provide a new nuance for PSG by forming a team that relies on collective play and also young talents later.
I mean if your only goal is to win UCL and the only thing you do is spending money, then you are bound to lose some money anyway and not get it. Just spending money alone doesn't get you a win, that is not how it works, you need to end up with something much better.
We should consider that they have never kept a manager for too long, and kept on changing their manager, that could be one of the reasons. They need to get some good manager, and a great director of football and let them do what they do for five seasons in a row. Right now they have Enrique, about to go on his second season, just let him run for 4 more seasons, I guarantee you that they will have a higher chance, even without Mbappe, because manager would create his ideal team.
Building a team without money is possible if they are able to produce a lot of good talent from their academy, but currently PSG does have a super luxurious academy but we don't see any good talent from PSG, so it does require PSG to look for star players to fill their squad every season, talking about the duration of the coach contract so far, indeed if PSG has never retained their coach for more than two seasons, including the current Enrique.
I don't know what their goal is to often give a two-year contract to the coach, but I think maybe they really want to see how good the performance of the coach is at PSG, so that even if later PSG's performance is not in accordance with the expected expectations, of course PSG will not have difficulties and also have to pay a large compensation for the dismissal of the coach, ashort time to build a team will certainly not produce an ideal team but on the other hand giving trust for a long time to the coach is also a big risk to the team, many experiences we can see how the club gives a long trust to a coach ,but the coach is not able to provide the results expected by the management and fans so far.