I think it is funny that anybody would think that the family in The Split have it all. The main character having the affair got more than she bargained for when she found that her seemingly wonderful husband had been seeing someone in the last series and proposition her sister. She's taken him back but she's obviously not happy with him.
If you've grown up with a fairly happy household with reasonably compatible parents, you may think these storylines are overly dramatised but I can tell you from experience that they happen in families across the country all the time and have been for centuries. The difference is, we now talk about it. I grew up with the pretence that my grandfather was my Uncle, at 8 years old telling the Nuns that my real father had died...I was on to my 2nd stepfather with a fair few Uncles in between and we were far from alone. There were alcohol problems, gambling addiction, serial adulterers, etc. From the outside they all looked respectable (even my cousins had no idea we were half cousins), holding down good jobs or having some standing in the community but behind closed doors, wow!