Believe it or not, traveling and partying gets old. Most of us have an evolutionary desire to have kids. You may not, but it can take time to manifest. Look out for feelings of hollowness, boredom or depression. Parenting may be hard, but I've never felt hollow or bored or that life has no meaning.
You probably didn’t mean it this way, but that reasoning emphasizes bringing beings into this world to avoid your own bad emotions, and not so they can experience their own good ones.
Giving kids a happy childhood and setting them up for happiness and contentment is of course implied. Either way, I think the vast majority of people who are alive want to remain alive, so I never understood the sentiment that it's selfish to bring someone into the world. It's only selfish if you benefit while someone else suffers. Bringing kids into the world is a win-win, at least in the developed world where birthrates are plummeting way below replacement rate. In this case it's a win-win-win (third being society).
What might be considered selfish is to not have kids when we are way below replacement rate, while expecting to be taken care of by other's kids in old age. Unless we reach AGI and humanoid robots soon, the food, housing, services and healthcare has to be provided by younger people.
> Either way, I think the vast majority of people who are alive want to remain alive, so I never understood the sentiment that it's selfish to bring someone into the world.
It's not "remaining". If you had decided to not have kids, the kids wouldn't be there in the first place, so they wouldn't (couldn't) feel any regret about.
This is possibly one of the worst sentiments to look for if you intend on having kids. I've seen families before where they had children solely to fill in that feeling of boredom or hollowness and when children don't fix it, they abandon them or become nasty parents.
