That regret has been forgotten by PSG and building a team that is more prepared to face the challenges coming next season and forgetting Mbappe. An experience that Enrique has to face to build a team which initially relied on star players and now he has to be pressured to be able to bring PSG to compete strongly in domestic leagues as well as in major competitions without relying on a star player like Mbappe.
It's a good time to build a team with young players or build new talents from recruiting young who can contribute in the long term and it's one of the best ways than spending large amounts of money on star players who can't last long and also give big losses. Nasser Al-Khelaifi seems to have already realised that building teams with star players won't give you a reputation in the longer term and building teams of reliable young players better guarantees a better future for the team.
There is nothing to regret because the interests of the team are greater than those of the individual. In fact, in my opinion, Mbappe is just a burden for anyone and it is difficult for any coach to determine his policies on the field. Now PSG must develop a clear road map to be able to compete domestically and in Europe. I think this transfer market must really be utilized well in order to get players who match the vision. I am sure that PSG remains a big club and they will always learn from their mistakes for the sake of a brighter future for the club.