It is amazing to me that the same person who will be self-righteous in refusing to hire a maid will have no problem at all ordering an item on Amazon (where countless faceless staff do 'potentially unpleasant logistics labor' to get that package to your doorstep).
Paying to have my home cleaned feels uncomfortable because it's something I could do myself, so it makes it very obvious that my time is being valued more by society than the cleaner's.
I generally find people who work for cash, and we negotiate fair prices.
I don't think that works as an explanation. I have no compunction about buying hot food even though I can cook myself, and I'm sure I could easily have learned to repair a couple of things I paid to have repaired for me.
In most service industries, you have people serving many different customers at once in a way that's usually more efficient than every individual doing the work. But if I pay for a cleaner, I'm paying someone to spend time doing almost exactly what I would do otherwise. They're probably slightly faster than I would be, but otherwise there are no economies of scale obscuring the inequality, and that's what makes a lot of people uncomfortable with it.