He showed zero growth and that he was okay and willing to do the same that he went through as an LBS. That other woman, his now wife, is going to encounter a world of hurt when she finds out about the affairs and that he doesn't really care that much about her. How can he put her through such crap after what he was put through? I just shake my head at it. Definitely not something most LBS here would do.
It's hard to say if they were meant for each other. I find the concept of the 'one' or 'soulmate' hard to grasp - I think there's tons of options for each person and it's how we can make it work.
I think she was still seeing him because she has a need to be wanted at some level. That he can be Plan B and she can eat the cake and have it too. I guess familiarity makes things easier too.
Part of it could be that they are the same underneath - but I think that's a pretty callous view. He had the opportunity to be much better but he chose not to be that way. I think she's trying to find peace but you're right that she's not happy.
I think a better ending would've been if she'd ended up with someone else, or alone for a while, or being a serial dater. All of those are plausible options depending on where she was with her emotional and personal growth. Ideally he would be in the same place too - finding a co-parenting rhythm or at least parallel parenting.
He had way too much fondness for her throughout, even when she was pushing him to the limits and that was weak behavior. He salvaged it in episode 4 when he rejected her idea of trying again. I thought he'd turned a good corner there.
I think till episode 4 the show was very strong, but the last episode was much less believable.
