How Kyungsoo turned out the better Dad than Dojin?

In what way?

Kyungsoo readily accepting Bin as his even though they're not by blood and trying to foster a good relationship with Bin's grandma. Kyungsoo is a good egg.

Dojin is an okay dad, I just prefer Kyungsoo more as a dad.

let's not compare they have different situations and personality with diff wifu

Uhhh, u can't say he's "better". Cuz for me dojin is better. He took care of byul on mostly his own after hyesung ran away. Respected hyesung's decision when he didn't want to see his mum(family). But kyungsoo here is just a lil toxic imo. He is a nice guy sure. But really? Secretly rekindling with your spouse's family, and the same family which gave chowon trauma and turned him toxic. Nah gurl that just didn't do for me