You "can't" make a one stop shop for electronics, not at least how things are done right now.
Different projects will have different reasons for choosing transistors: maybe response time is maximally important. Maybe they're using the transistor in "linear" mode and would rather have a wide and consistent ohmic region. Maybe its a high-power application where breakdown voltage is most important. Maybe it needs to be ruggedized and they'll prefer protection diodes.
This is _JUST_ transistors. Every other part basically has this similar problem.
There's just too many important decisions per part. As such, modern nmos-transistor catalogs number in the thousands of parts in practice. The only way you get the right transistor is through online ordering through megastores (like Digikey) who can keep stock of all the hundreds-of-thousands of SKUs + have an online searchable database to help you find what you're looking for.
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So where Radio Shack could feasibly work... is by:
1. Shrinking the catalog down to "standard" generic parts that have wide applicability to many different projects. "Jack of all Trade" transistors, that aren't the best in any particular category but instead have nice behaviors across a large set of axis. This is just for a "keep in stock" perspective, for anyone who wants to "make an electronics project today" without waiting for the 5 to 10 days for typical shipping times for custom PCBs.
#1 means that Radio Shack (or other stores) can swap between transistors from different manufacturers as they come into (or out of) stock, or based on supply/demand. (Buying up excess stock from a factory on the cheap), etc. etc. But still organizing these parts to match various SKUs that match particular use-cases (ex: 3.3V logic NMOS).
2. Focus on physical attributes which benefit to coming into the store. Ex: Serving as a central point for expensive tool rental. An OEM-set of crimpers, for example the Harwin M20 series of Dupoint / Mini-PV clone connectors, has a $570 crimper. That's cheap for a store to hold in stock/rental, but a bit expensive for hobbyists.
Electronics in practice have _LOTS_ of $500+ tools (crimpers, 3d printers, laser cutters, etc. etc.) that really would benefit from rental-models. Furthermore, the tool usage scales well with wire usage in practice. (Ex: bulk ethernet cable is way cheaper than individual ethernet wires. If hypothetical-Radio Shack buys 10,000 ft. spools and has the nice $500 to $1000 crimpers to make your own wire in store, that's a good reason to come in)
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With 4-layer boards so cheap in practice through online ordering, I really don't think "Hypothetical Radio Shack" can compete with that.
But give me a place to consolidate custom wire lengths + rental of those expensive crimpers, and we probably have a deal.