I dunno - I see this as a very complex subject.
For items I already know about, or perishables/consumables I'm just restocking on, online is the only way for me unless I run into a killer deal at Costco or somewhere.
For higher ticket items, it really depends on the item. I ordered my last TV from Amazon because I was able to do enough online research to be comfortable doing so, and have been happy with that purchase. When I bought my last laser printer, I went the other direction and spent a good hour at Staples deciding on which of my top three I would choose. That included not only verifying size (and there's a big difference between seeing, and even measuring online dimensions, with seeing the actual unit) but also being able to run the demo programs on the printers and run through the menus to see how everything works. Staples actually ended up being cheaper than Amazon for the printer I chose, and also price matched Amazon on toner. Since Amazon would also charge me sales tax*, Staples was the clear winner.
Shoes are an item that I really want to be able to try on, but are also items that do better online. I never see New Balance in wide sizes locally, and beyond that, a local store, even a specialty store, can only stock so many shoes. Amazon and Zappos have thousands of choices and very good exchange policies if the shoes don't work out.
Vehicles are now items that are being bought sight unseen. Regarding generations, I think this is a good example of younger generations heading in that direction. I'm not opposed to buying a car off the Internet, but the old guy in me won't let me make a $40K purchase sight unseen. I want to sit in the car, examine the car, and test drive the car.
The retail store model is also simply becoming too expensive to support. I don't know that it's the retailers' fault. Places like Amazon are simply much more cost effective. When you have to pay for brick and mortar retail space, and keep yourself well stocked to allow the browsing and "hands on" shopping, you also create a burden for yourself that online retailers don't have.
I think brick and mortar retailers will slowly evolve to something else, though I don't know what. I don't see Walmart going away when they can still provide something like a case of water for 50% less than Amazon. Bulk shipping of items to retail locations is one area where retailers can possibly still save themselves. It's much cheaper than individually shipping, especially heavy items, to individuals.
*I believe it won't be long until everything purchased online gets hit with sales tax (in states that have sales tax). So in something like my Staples example, when it's a relatively expensive item that lends itself to "hands on" inspection by potential purchasers, having the item local at a competitive price could sway many people to get in their car and drive to the store. It still requires brick and mortar retailers to figure out which items lend themselves to "hands on" vs " I don't need to see it first".