They need to crack down on them. There are many with no FCC certification, and many that are certified as either Amatuer radios or FRS/GMRS radios that are being sold as professional radios. I have had to answer way too many questions from people who have bought that cheap stuff and want me to support it for them. When I tell them they aren't legal to use they get mad at me for it. I have even conversed with some of the people selling the stuff and they are clueless as well.
There is even a new generation of radio dealers who are selling this stuff on their own websites under their own brand name who are clueless as to what their products are authorized for. I've had some tell me that their Amatuer or FRS authorized equipment was legal on business channels as long as I had a license for it.
Lot's of CCR Part 90 radios are also being sold outside of their certified parameters. I have looked at the testing reports from a bunch of these. Some of them were certified more recently, with 6.25 kHz ANALOG in the test documents. Not a very feasible mode of operation, and the actual radios sold will only do 12.5 kHz analog.
It's good to see Amazon stepping up a little but the FCC also needs to do a better job of looking at what the labs are submitting and not just rubber-stamp everything.