USB Type C is a connector. Like USB Type A is a connector. Or Type B.
You can have Thunderbolt 3 on a Type C connector or you can have USB3 on a type C connector. USB3 is also seen on a Type A connector, and also a variant of Type B and micro B connectors. You can even get
DisplayPort on a USB Type C connector.
I've not seen any USB3 over Type C devices mistakenly marketed as Thunderbolt 3, nor vice versa.
Still, yes - when you go to a common connector for different thing, the tradeoff for those benefits (which I think are huge*) is the end user has to actually do a little research to understand things.
Again, "Type C" is connector -- you're confusing the connector type with the data protocol (TB3 / USB3 and it's flavors)
If manufacturers are lying to or misleading consumers, that's NOT the fault of the port or technology. So don't blame USBC or USB Type C for scummy vendors trying to make a quick buck with substandard stuff.
If a company is fraudulently advertising a capability it doesn't have, you return it. File a complaint with the retailer. File a complaint with the FTC or appropriate governing body where you live. In the mean time, do your research and read the reviews before you make your purchase.
Sure, if you buy some cheap crap it's likely not to perform. So READ REVIEWS and see what it is you're really getting. Guess what, just like always, you need to do your own research.
If you want the most out of a dock/hub, go with a Thunderbolt 3 dock. Of course, you have to spend more for it. Thunderbolt hubs have always cost a bunch. If you're okay with USB2 ports plus 4K display, then a USB3 class hub will do the job for a lower price. Just don't expect TB3 performance from a USB3 hub.
(*) benefits -- I can connect power to whichever side of the computer is most convenient and least in the way. Same for external video or ethernet or external drives. Left side, right side, doesn't matter. Whichever works best for the situation. Huge plus vs. the discrete port type scenarios from years past where your power connector was in the same place no matter which side your outlet might be on in that particular place you're working. Or which side is more convenient for the external video connection - used to always be in one spot regardless of situation.