I don't get it. Why bother faking something that is very cheap to make genuine? I mean you pay peanuts for real deal, and you want to make something even cheaper then that?...why? Where is the profit?
First, when you make millions of a thing, then saving even fractions of a cent add up to a lot of money. Chinese manufacturers favor high volume, low margin products. Second, Maxim parts are not cheap, in fact they are among the most expensive in the IC industry. A single DS18B20+ goes for 3.47€ on Mouser right now. That's a juicy target for counterfeiters.
I don't know where you are, but in my country I paid the equivalent of 4 cents for DS18B20. I hook it up to my multipurpose Raspberry Pi and I use it to measure my room temperature. I bought 2 of them, for redundancy reasons when lockdown started. The other one is still in original package.
Well I guess when you invest in purchasing fab you want it utilized as much as possible, so you might want to add batch here and there when you dont have contract work.