I can attest to this. Big part of the reason why is that dad's teach the kids to treat mom like a maid.

Oftentimes she contributed to this too, by feeling like she has to do it all to prove herself.

Regardless of the myriad of cause and effect scenarios, you do less work post divorce in large part because the kids stop making unnecessary messes and start picking up after themselves. You can teach them to rinclse our their dishes and put them in the dishwasher or stack them by the sink, pre-treat their clothes with stain remover, work a punch list, add something to the grocery list or rotate stock when they take the last one, fold and put clothes away, etc. They learn skills and start to take pride in their home too.

You can always tell, so profound is this difference. My daughter pointed it out to me. Her classmates in nuclear families tended to feckless and helpless. They couldn't do anything for themselves and got frustrated very easily and started whining. The kids from single parent homes could look after themselves and adapt.