I don't think there exists a single remaining RadioShack store in the US. The website appears to have everything on clearance. I think they've essentially just bought the name, likely very cheaply since virtually nothing else exists anymore.
Heck, in the valley, IRL fulfillment (willcall)/retail of electronic components is limited: (Halted isn’t organized and sells mostly used stuff without ESD management anywhere, Fry’s is a joke). Maybe you can will-call some places (Jameco), but the main sources like FleaBay and DigiKey don’t compare to IRL/right-now like Shenzhen highrise of everything bad fakes, good fakes and authentic. If you’re prototyping and about to do small runs it’s much easier in China because suppliers of all sizes and contract manufacturers right there, and can turn-around PCBs in a couple of hours. America doesn’t have anything remotely close to the density and rapid business efficiency of Shenzhen.
Yes, many things get cloned in China. But I have, as yet, not seen a single thing cloned that uses the same design as the original. I'm not saying it doesn't happen, but I don't believe it to be the most common case. Very often, the copies of a design use local parts that western designers would never choose or are unaware of.
When making clones, the goal is rarely 'make it exactly the same.' More often, it's "make it look the same or work similarly, but cost much less to make." In most cases, a sketchy manufacturer is better off just doing a not-quite-cleanroom reimplementation of your design.
For example, there are clones of the APA102C 'smart' LED that Adafruit sells as a 'dotStar'. (One is branded the 'SK9822'. Some are sold as 'APA102C'. In a VERY weird twist, APA in Taiwan who made the original is now reselling one of the clones as the APA102C-something.) The external appearance is the same. It speaks roughly the same protocol. But the IC inside is a completely different design. In a couple ways, it's a nicer LED, with a couple extra features. It's cheaper, too. But in my use case, it behaved oddly.