I was single the first time and, to be honest, it was easier. My current partner is a lovely person, but dealing with their stress on top of my own is an extra burden.
Relationships fail for many reasons but I'm guessing dissatisfaction is close to the top of the list. I can cope with over-caring but I'm not keen on indifference. If the person involved thinks I'm sorry responsible for cleaning the communal toilet ( even if I've spent the last three months with one end or the other stuck in it) and won't accept things have changed, I'd struggle to figure out why I was involved with them. Mxx