I have a good friend like this, and, fond though I am of him, I can see he would be awful to be married to. Since we've been friends, he's been married, divorced, had one relationship of about 18 months and is now living with someone, so I can see a pattern.
In himself, he is a low-energy, passive, routine-bound individual (and although he's 57 now, he's been like this as long as I've known him).
When he is in a new relationship, he is temporarily excited enough to be semi-dynamic, plan things, get out of his routine. Then, when the newness wears off, he returns to being someone who just wants to be at home scrolling around on his iPad on the sofa, and to whom what would be a minor routine chore for most people (taking the children swimming, buying shoes) turns into something that takes up a whole weekend, and after which he can't be expected to do anything else, because he needs to recover.
I remember once describing to him a very ordinary weekend, where I'd taken DS to his football training, DH picked up stuff from the farmer's market and cooked brunch for a couple of old friends at ours, I met my sister for a coffee and a walk, and DH and I went to see a film that night, and the day after we saw DH's parents, took a bunch of DS's friends to the beach with a couple of the other parents, did some grocery shopping and household chores -- and he kept making huffing noises of disbelief, as though I'd just climbed Everest while balancing a book on my head and learning calculus.
He also has a habit of borrowing the hobbies, friends, lifestyle of whatever woman he's in a relationship with, and when he's between relationships, he does literally nothing at all other than sit on the sofa at home, when he's not at work. He sort of goes into 'neutral mode'. He also thinks women's role in his life is to (I quote) 'keep me up to the mark'.
Unsurprisingly, women get tired of this.