The money isn't an issue. She definitely didn't make that decision to cash in and be done with it. The payout is almost irrelevant. Now Roman, for example, makes perfect sense. He doesn't want the job, he doesn't want the family feuding, and he doesn't want all the bullshit that comes with it. He's done. He's completely broken and checked out. So if we were talking about Roman here, then it would make much more sense. I actually think how it all ended with Roman was perfect.
In fact, you could make the argument that he was the "winner" here. Certainly more than the other two. He's out. His father is gone, and while that fecked him up, he doesn't have to be forever dealing with that toxic relationship. He's dropped his facade, he never wanted the job but couldn't admit it. So now he doesn't need to deal with that bullshit anymore. He's free. He's still a mess, but he's in a better place than the other two. I have no problem with how that arc ended. I think they did an incredible job there.