The internet was a paradigm shift… full of unknowns. I think you are underestimating those challenges. We only speak about Amazon now because it was the one that survived.
pets.com also failed to make it through the "carcinization" of online retail, but wasnt nearly as notable a failure because it was attempting to start an online retail business from the ground up, versus Sears' failure to adopt online retail to their already-successful B&M model. I think the Sears mode of failure is much more spectacular because it had previously thrived on a business model that's almost analgous to Amazon's, threw it away, and failed to recognize it could be effective again.
pets.com also failed to make it through the "carcinization" of online retail, but wasnt nearly as notable a failure because it was attempting to start an online retail business from the ground up, versus Sears' failure to adopt online retail to their already-successful B&M model. I think the Sears mode of failure is much more spectacular because it had previously thrived on a business model that's almost analgous to Amazon's, threw it away, and failed to recognize it could be effective again.