100% they do mean it.
I never really wanted kids. But me and a friend had too much to drink one night and I was a dad at 22. It's the best thing that ever happened to me. Now I'm 30 and have 3.
People tend to focus on what you give up and not what you gain. Parenting presents a huge amount of moments and activities and feelings that you would never get otherwise.
Both paths are good. Just different.
I wouldn't trade the first time my daughter said I love you for anything in the world. Or even the first time she smiled. You could offer me any amount of money or holidays and I wouldn't go back and miss that.
I have a good support network so I can still go out when I want to. I could go on holidays without them if I wanted to. I could buy them less stuff and myself more. Nothing is stopping me.
But I wouldn't trade a moment of it.
Definitely. And plenty who regret not doing it. Such is life.