I sell physical prints mostly out of the fear of someone reselling. Like you said, they could still do that with a physical copy by scanning but at least that’s a little more of a hassle. I’d also hate to see my art printed on shitty paper or the colors are completely off because the buyer (or print service they use) doesn’t put in the effort to get the colors just right.
The thing about selling downloads is as a customer you get the product with in seconds or minutes after making the purchase. But I get there are some extra steps involved when buying digital downloads. You can also upload to various websites as opposed to goto nearest print shop. I think what I plan to do is offer both but offer the physical print as a empty order and when you order it you tell me what image you want printed. That way there is less confusion on what you are ordering.