Just popping back to say-
I don't think this is about whether having a role as a homemaker is worthwhile once the kids are at school. Badvoc and others have made it clear that they make other contributions by volunteering; and also, we shouldn't take it for granted that being busy is an end in itself.
The OP was asking: what can I do to persuade my OH that what I do is legitimate, because he is sulking? in later posts she clarified that she did work outside the home when her first DC was young; with her current children she doesn't want to, even though they are at school, because it's nice and she has more time.
The advice to OP is that her best case is not that she is working as hard as he is. He won't believe her, and to be honest it's not her best argument.
Of course we are all very busy when they are tiny. But it changes. By the time mine are say 30, 28 and 26 I am not expecting to be busy with them at home; I was very busy when they were 6, 4 and 2 (which is when I went back to PT work). By the time they were 11, 9 and 7 I was less busy again and so I went to FT, but locally.
At the time I went back, work was quite junior and home was pretty busy, so there wasn't that much difference. I recently had some time off work following surgery, so I got to compare a senior job (which I have now as I have been back at work for so long) with life at home with three DC out all day at senior school and Uni. There is no question, even allowing for the fact I was recuperating: it was way, way less work.
It's difficult to make this point, because ppl feel that we don't value motherhood, or homemaking, or that we are obsessive. In fact, I may well feel that there is nothing wrong, at all, with having a more leisurely life and spending spare time on volunteering or walking the dog. I'm looking forward to it myself, when I retire, and i don't mean that to be snarky. If I could afford to retire early, you bet I would. But I need the pension scheme.
So it's not that we don't value homemaking. We do realise that the pre-school years are busy- we had the same experience. but on the narrow question of: whose day has the most in it, the evidence does show that ppl who are employed have more in their day that is compulsory, than ppl who are at home with all their kids in school.
So the OP needs to find a better argument if she wants to agree this lifestyle with her OH- as many ppl have successfully done.