Ligue 1 will not lose its popularity but PSG will lose its dominance. I actually think that without Mbappe, other teams will have the opportunity to eliminate PSG's dominance. Yes, PSG is still the #1 favorite for now, but at least they won't be as dominant as they were when they were with Mbappe. We might be able to see where PSG has to fight to win the league championship, unlike this season where PSG really dominated Ligue 1 with a goal difference of +48 goals and collected 76 points, 9 points ahead of Monaco in second place.
I don't believe Mbappe leaving PSG would make them not dominate the French league. They still have so much money more than every other team in the league. They still have to money to sign the best footballers in the world, other Ligue 1 teams don't have that luxury.
Without Mbappe, the coach just needs to build his team around other players. PSG have a good coach in Enrique and he knows how to manage a team.
PSG still have a few signings to make in other to strengthen their team. They need defenders midfielders and also attackers, but the problem with PSG is that they always make the wrong decisions. I don't know how they always seem to neglect their midfield and defence and focus only on attack.
I believe PSG would still win the league comfortably next season, and yeah I also believe without Mbappe, the recognition of the Ligue 1 would reduce a bit.
Without Kylian Mbappe, PSG will still dominate league 1 but will not succeed in the champions league and this is a simple understanding of what PSG will experience in the coming season when Enrique has to come under pressure from PSG's previous dependence which currently must be changed instantly. Competing with cooperation between other players creates greater strength and I think at the start of the season PSG will experience a little difficulty.
PSG still has Kolo Muani and Goncalo Ramos who will later be Mbappe's replacements and these two players are one of the striker players who are under pressure to be able to perform like Mbappe, while Goncalo Ramos has just joined PSG and cannot yet provide proof that he has the skills. better.
I agree with you that PSG often focus on the attack line and ignore the importance of the role of midfielders who can always provide a big boost to the strikers to be able to score in large numbers and now in the coaching era Enrique must be able to try to prioritize all lines.