I left a 6 year relationship full of tiny disagreements about tiny inconsequential things, that would regularly snowball into whiny accusations (on her side) and feelings of betrayal on both sides. I’ve read some books about this since and I’m pretty sure I’d be able to handle most of it much better, but I’m also sure I wouldn’t want to end up in a similar relationship again. No matter how tiny, disagreements are still disagreements and take energy and time to resolve. I’m willing to invest some (quite a lot actually) into a relationship, but not all of it.
I’ve been with a different girl for five years now, we got married this year and it’s been a breeze so far. We’ve both made some mistakes (like regular everyday stuff) in those five years, but AFAIK we still deeply respect and love each other. The difference is night and day.