I think some folks are missing the point and deliberately.
Sure a house in need of a bit of a Hoover isn't a big deal. But, irrelevant of the cost, if you walk into a dirty house, it seldom elicits "oh what a lovely house, I'd love to live there". It usually only attracts people who want to low ball the seller and get it cheap.
I do think though, that some people just live dirty. Dirty dishes piled up in the sink, sticky crumb laden work surfaces and floors, dirty towels and bed linen that's not been changed for weeks, floors that need hoovering, rubbish laying about, clothes all over the bedroom floors.. I genuinely think it's some people's norm. For a variety of reasons, mental health, laziness, not caring,
The op is right. If you want the best price for your property then cleaning it and tidying it up, presenting it at its best, is one of thr basics. And if you present it dirty, then it's either going to put people off or attract the kind of person who sees it as an opportunity to low deal the seller.