Marseille should learn their lesson from this result. They couldn't compete with Lens for the second position until the end of the season. Lens even completed the season 11 points ahead of them which is really a horrible look for Marseille. The second position was important because it is the last slot for the Champions League group stage. Lens definitely deserved that.
Marseille will have to play qualification games and I don't know if they can even reach the group stage for now. They will need to realize where they were doing wrong to not repeat it. The new season will start earlier for them so they had better prepare themselves well.
Marseille is actually playing very well this season but they still have to improve so they can be better and can be a competitor than Paris Saint Germain at the top of the standings this season they are another class with dance in second place but overall they are playing quite well. Inconsistency is a nightmare for all teams, not just Marseille, Paris Saint Germain also feels the same way.
Talking about inconsistency will never end because every team will definitely encounter this every season and for Marseille maybe that's what they experienced at the end of this season. We know very well that not always a good start to the season will last until the end of the season and sometimes there are things that make a team fail to maintain consistency.
The most common case is when several players get injured in the middle of a season it can be a very detrimental thing and there are many examples of other teams from other leagues experiencing the same thing and not only teams in Ligue 1 who experience it. I think this problem can't be solved as long as a team doesn't prepare anything in the future and it's something that will be difficult for anyone to handle.