The problem is that if it is a really good quality product that ALSO makes some revenue, I doubt people are looking to sell on those sites. You have to go hunt yourself. Once in a while, you may be able to find a Gem on those sites but yea, most are not worth the time/money unfortunately if you are looking for something more than a simple side project.
FWIW I have multiple revenue generating businesses that I'd be open to selling for the right price, but IMO there's nowhere to list them that warrants my attention. I don't want to list my business alongside bunch of $0/MRR side projects asking $10k.
