Brick and mortar is the largest part of my business. I think of online as a support structure to the real life presentation and sales.
In person, the buyer can see the detail, see the quality, see how it's printed and framed. Hold it in their hands. That's a big big part of selling art. The in-person impact, both of the art itself and of the presentation. It's right there, it's ready to go home with the buyer - so if they see it and love it, there are almost no barriers to them owning it. It's work, though. I keep inventories for 4 galleries, I have inventory at the studio, I hand deliver work, I make myself available on the phone or in person for shows and customer questions.
Buying art online can be a chore. Buyers have to pick the materials, figure out the differences, think about shipping. Many folks don't mind that, or they even enjoy the options. But you have to recognize it's still a process, and one that may be foreign even to people who shop online for other products. But it's passive income. You've already done the work, and the sales that come in (organically or through gallery exposure), usually don't require any additional effort from the artist.