Without seeing some financials of some of these companies, correlating that against the economy and changes in population, it's all very hard to see. Here's two impressions:
1. Brick and Mortar stores of all types are in general competing with online sales. The little town I am from seems to have exploded in restaurants and micro-breweries, whilst the small locally owned business of supply <insert whatever you want here> is struggling. Even local entities like pharmacies are under siege because insurance companies are pressuring people to buy their regular meds from online discounters. The variety, the convenience and the price point are just hard to miss. There are many examples of this shift at least in our town.
2. At least in my age group 40-50s, I have a number of friends who never smoked in their lives due to the big anti-smoking campaign in our childhoods, pick up in moderation cigars and now pipes in the last few years. One friend is even into shisha. If they do smoke, it is in private in their homes AND they buy online, so it is underground as there are few public friendly smoking places. They shop online not because they don't like Brick and Mortar stores, but it is convenient, the variety is great and the price point is competitive. I get it. Do I drive 40 minutes to my B & M in a very full work week, or do I buy online and it is at my house in several days? I try to go to my B & M to support it, but sometimes an online order is what I wind up doing.
I have also wondered if vaping and pot smoking will also lead to others picking up the briar, but I couldn't say from any personal experience as all my friends don't fit that profile.
Anyhow... time will tell...