No. Children helping out and working to support the household or just because they lived in a household with lots of work, like a farm, is not the same.
And no, that wasn't the main reason people had kids back then. The main reason people had kids was because they liked fucking, and goat bladders make awful condoms.
Yeah, not really. At least insofar as everything I've seen regarding marriage and suchlike in most historical societies goes. Marriage, procreation, family creation... they were all a lot more practical, if you will, for most of human history. People didn't have kids because fucking is fun (though it is), they had kids so they'd have farmhands and things to barter to other families for dowries and suchlike. Partner choice was more about family connections and fecundity than anything else. Romance and reasons beyond what were essentially economic hasn't really been a big concern insofar as that sort of thing goes until very, very recently (in a relative sense). You had kids because you needed kids to tend the land (/send off to work/etc.) and keep the family going, and you wanted as many as you could get because that was how you made sure those two things happened.
Net hiccup made response come after, but... I think it still applies. Most of our history it was more or less the other way around -- sex being fun
was the benefit. It was the kids you were after.
You honestly can't see any difference between kids helping out because they have to in order to get by (and because the only way to learn a trade was apprenticeship) and a man gathering as many children as possible and raising them in Aw cheaply as possible in order to turn a personal profit?
Yeah, there's a difference there, but it's divorced from the historical context MSH was talking about. It's only been recently that kids were anything
but a net profit, so that latter bit was pretty close to the de facto state of things. The primary reason they tended to stick to blood kin instead of orphans was due to concerns related to marriage and marriage equivalents, so far as I understand it.