Marseille are far less quality than PSG with players they have and only a coach is not enough to make their squad becomes stronger a lot to be competitive enough and be able to beat PSG.
PSG will have a transitional season without Mbappe after many years but with all star players they have, their strength is good enough to win Ligue 1 again. This is challenge but also opportunity for PSG to build up a new squad, without Mbappe, and taking this chance to get rid of too much dependence on a single star player. A new era is coming for PSG but will the succeed in Ligue 1 and continue their domination or this new era means chance for other clubs in France to challenge and beat PSG in next seasons. I am keen on a first scenario, a continuous domination of PSG in Ligue 1 because they are simply rich and can improve their squad easily.
I mean it's obvious that Marseille is a lot worse than PSG, and Monaco is also not as good as PSG neither. However, when it comes to betting, those two comes in and second and third place, most places have them at equal chances so second place so that means they are pretty good.
But that doesn't mean that we are going to end up with anything that will be too simple for PSG neither, we have seen them lose to Lille before, and this year they do not have Mbappe as well so it could totally change some stuff, we may see something changing. I am not saying that PSG will lose, because they may end up not losing at all, but I am saying that we are going to end up with something that would be possible, the possibility is there.
I sense that PSG may end up facing some issues adjusting to life without Mbappe, and they are not that great at midfield neither, so things going to be a bit troubled for them. Lets see how they are going to do, but I can see that Marseille may have a chance if they play a decent football, I am guessing that PSG will get a lot less points than they did last year, which means that if Marseille improves from their last years performance, or Monaco does, those teams may have a shot.