I think it has to do with the child, too...if you have calm, content, self-entertaining little ones you can get an awful lot done in a short amount of time.
Mainstream moms might either force their child to do without mama (playpen, crib, high chair etc) so the child is just used to not being tended, or they may try to give baby alot of attention generally but ignore while cleaning.
With my first and third babies, they were happy to play on the floor or ride in the sling while I cleaned. With my second and fourth babies, I was chained to the rocking chair and when I got to get up I wouldn't be cleaning! I'd be peeing or showering or eating or cooking...Dh did most of the cleaning then.
But high-needs or not, by the time my youngest child is 3 or 4 I can keep a clean house again LOL Toby's 'very' high-needs and he's only 2, so I have awhile to go before we're consistently clean.
I can get the place ready for company in about 30 minutes and I think that's good enough.
There is nothing wrong with using a high chair if used moderately. My toddler LOVES his high chair. When I am doing dishes, he sits right by me and I give him dishes to "wash". He also likes it when we have dinner, because he can sit right there at our level and eat and be with the family.