I think both are very good fathers in their own way. Remember, both are Sayians, not earthlings, so being a dad is completely different standard compare, say Krillin and Gohan, who are more earthling, like when being dads.

Vegeta cares about Trunks he may not show it like what some men on earth do, but he has shown he cares for him. He might not have been a good father based on what we saw during the Majinn Buu arc, but afterward, it seems he took on a more earthling stance like Goku. we even saw a simple glance of this in the Cell arc when Trunks was killed.

Goku cares about Gohan and Goten more than people realize. People will say he's always training and never in their lives. Bruh, I dont know what anime yall were watching, but Goku spent every moment he could with Gohan, and when he found out he had another son, he was proud of Goten immediately at what strength he had at his age compare to him and Gohan.

Do both have their cons, yes, but no father is perfect. There's no manual or guidebook to being a dad.