the only B&Ms that will survive are those with a very strong online presence
Not true, exactly. For selling pipes, yes maybe. As long as the store finds its niche. But, how can any store offer prices for less than the original wholesaler on tobacco (unless they just choose to sell it at cost, no profit), when the wholesaler has chosen to compete with you? The main online venues that we go to to buy tobacco, are also the wholesale distributors for various blends. Plus, those strictly online venues don't have retails costs to pay. A storefront is way more expensive to maintain than a warehouse.
The one thing that a B&M has to offer is location. I can go to The Briary on a day off and set and meet the most interesting people in Alabama. Various pipemakers will drop in. The owner is very entertaining. And, someone will invariably come in with something interesting with a lot of age on it to share. It's always a lot of fun. You get to meet new pipesmokers, show off pipes, and talk tobacco... in analog.