A dishwasher is a game changer, especially if you have a baby, but even if you don’t. No need for a drying rack, no guessing if you cleaned well enough, and less water usage.
And I don't really have a feel for whether more cleanliness is a benefit compared to the hormetic effect of exercising the immune system.
Could you elaborate on this? My understanding is even if you're using a sink/basin filled with soapy water this is still almost always less efficient than a dishwasher.
Do you own very few dishes or something? That's the only reason I can imagine not being able to fill it before needing to run it. Even before having a kid my wife and I could easily fill the dishwasher daily since we cook quite a bit.