I’m not sure you’re going to get an objective answer to this as no one has lived a life of either having kids or not having kids, hungrythirstyhorny.
I will say that, as a single male in his mid forties who has observed a good amount of life; first, the thought of not having people to rely on in you’re old age is a little worrisome; and two, not having had someone to pass my knowledge and skills down to is a little sad. However, I really enjoy the freedom and opportunities my life (and bank account) affords me.
There is always a cost to freedom. Or, as Jonis Joplin put it - freedom’s just another word for nothin’ left to lose. Choosing to not have children is a selfish act. Whether “selfish” is a bad thing or not is subjective.
I would offer that anyone who’s going through life without children, find some altruistic outlet to participate in. You can otherwise find yourself wondering what your legacy may be or what the point of your life has been - aka a mid-life crisis.