Nothing personal with those businesses but some of them (you know who they are) are exploitative and only help to aggravate the ever increasing inequality.
It's very easy to scoff at "cheap labor" when in my experience it's far more often than not, the entitled , incompetents (they pair often) who complain. Just because someone feels entitled to a <£ some high number> salary means they are worthy of it. In fact, oftentimes not!
If I'm trying to rent out a place and nobody wants it, then I need to adjust my price expectations if I want to rent it.
I am one of the "evil" business owners you speak of, and there is no way I will pay the exorbitant salary expectations from (mostly) undeserving people. I would much rather outsource and hire people in Ukraine, Russia, etc. Sorry to break your heart, but If I pay $x then I would expect $ x+<delta> value from hiring someone, that's the core of any business.
To use your analogy, if I am trying to rent out a place, and it's basically a tent & a sleeping bag (which in the current job market it is) , I would focus on making it worthy of the asking price or lower my ask.
Sauce for the goose == sauce for the gander.