Honestly I don't think a one-stop-shop can be unassailable. Having a depth/variety of products is important, not just for consumer's sensibilities but also for being able to cover all the use cases. A Walmart might be most of a grocery and pharmacy and toy store, and half of a garden and hardware and auto parts and home furnishings store, but it will never be all of all these things (and perhaps not even 100% of any of these things). The logistics just becomes prohibitive.
The businesses that are best to start with are the ones where online shopping is unsatisfactory.
Funny you should bring up Walmart, because Walmart is the second biggest reason why I hate the “just start your own business” cliche.
Walmart was weaponized to make that impossible.
Honestly I don't think a one-stop-shop can be unassailable. Having a depth/variety of products is important, not just for consumer's sensibilities but also for being able to cover all the use cases. A Walmart might be most of a grocery and pharmacy and toy store, and half of a garden and hardware and auto parts and home furnishings store, but it will never be all of all these things (and perhaps not even 100% of any of these things). The logistics just becomes prohibitive.
The businesses that are best to start with are the ones where online shopping is unsatisfactory.