I don't know how I cope, I suppose five children is my reality so I don't compare myself to those with none/less.
As for affording it I have a good career, a low mortgage in the North West and a generous mum 😊
I don't know why the environmental impact doesn't bother me. Honestly if the UK birth rate was higher I may be more inclined to worry.
I don't think my children are disadvantaged materially by their siblings, certainly I would worry less about money if I had less children and I would have more savings but my children currently have the same things their peers do.
I have a people carrier, holidays are fine but yes, very expensive and necessitate a babysitter on occasion. We usually holiday with family/friends amd OH and I get a couple of city breaks per year.
Housework is the bane of my existence ditto laundry.
Best of luck Birthday!