I believe you meant it in a matter if lewds but not content in general.
Because Mina's had the most screen time with the MC so far — I think even more than all the other girls combined (the whole story basically revolves around her plotline).
Also, I don't think Maddie is forced on MC, plot-wise, it's the way the story goes, they start as friends with benefits, and to show the gradual transition from FWB to lovers, some scenes needed to be shown 1st, all content/scenes look natural. The same with other girls including Mina.
Disagree, it goes both ways, when MC feels down - he calls Maddison, and vice versa, they both benefit from this relationship, it's literally said in a game (the scene where MC says he feels bad for using Maddison). The whole idea is that at some point Maddison starts seeing MC as smth more than just FWB, and it's up to you, the player, to decide whether you wanna go down her path or not.