I don't think it's taxes so much as compliance cost of setting up and running a location. BigCo can hire specialists to figure out "ackshually no this is why my site plan is compliant than you very much" and hire them at cost whereas the local guy has to get kicked in this dick by some hired engineering firm's or law firm's profit margin for the same service aaaand gets a worse service on top because the local business who wants to keep doing business there can't fight for their client like some guy in an office at BigCo can.

Even if you control for the Amazon factor or the Walmart factor by looking at services, the bulk of these "successful" businesses are either chains or owned by a bigger corperate entity that can do kind of the same thing.