Even though you can "firearms" online, you still have to go through a FFL Holder. And, a lot of people are novice firearms owners or potential owners
they want hands on when they buy.
And, as long as people want to trade guns etc or sell guns etc the local places will be there.
Amazon sure has an impact on the non-firearm portion of shooting sports product lines.
Just look at the impact to J. C. Pennys, Sears, Kmart, etc as people do their shopping online.
Gander Mgmt or business model fails to realize if you lowered the prices you would move more product.
Now, look at the state of the Shooting Sports industry as a whole.
Federal laying off more people.
Unless there is a scare for some reason AR's at the entry level will be quite attractively priced.
And, without pressure to "buy now" people people will custom order stuff.
It would be near in possible for any brick and motar store to stock every possible configuration.
Not cost effective at all. As shooting buddy pointed out it would nice to have LGS that had
"Subway" style AR building center. Start with stripped lower and then walk down the aisle.
Buttstock and Pistol Grip, Fire Control Options, Other lower and upper parts. Barrels and flash suppressors. Handguards.
Iron Sights. Optics and mounts. At the end....get a bill pay for it and come back in a day for assembled gun be done with it.