I do, but the point i don't "need" one child - or 4. It's not like I need hands to help produce food for the family.
Yes, but, your words were "it is no less responsible to have four than to have one" (paraphrasing as yours had a typical I think)?
So, comparing it to say, long haul flights for beach holidays, would you say it was more irresponsible to have four every year compared to one every year or is it completely equal? Or comparing it to eating beef, would you say it was equally responsible / irresponsible to eat steak four times a week as once a week? Or food waste, would you say it was equally irresponsible to throw away one portion of a meal a day, as throwing away four portions?
Nobody 'needs' to have children. Arguably society needs someone to have children, but no, we as individuals do not need to have any at all. But, those of us who want to, usually do. Some of us limit ourselves to 2 as that is 'replacement level'. One in, one out (when a couple with two children between them both die, they will not have added to the population iyswim as they will be gone and have left two in their place. It isn't scientific at all, but that is the theory). So, having one child is better still, as you will have theoretically left one behind for your two iyswim.
Not judging you for having four btw. I have been saying all along that it is completely pointless and a little unfair to do so, as what the hell are you meant to do about it now and nobody should wish away people's children. But just explaining why one child or maybe two is more desirable for the planet than four in one household.