So, what would be the equivalent of film and physical media market dying for wrestling?

The rise of social media and YouTube as marketing platforms for wrestlers to get themselves over. It's so much easier now to find your own audience without being reliant on WWE or another company to do your marketing for you. WWE hasn't quite adapted to a reality where entertainment enjoyment is this fragmented.

Also, remember that Blockbuster's problems didn't start with streaming. They were going out of business when Netflix was still mailing out DVDs. Netflix figured out how to use the internet as a way to drive rentals, offering a bigger selection and more convenient options than a physical, brick and mortar Blockbuster store could.

Kodak was also well positioned to take advantage of the move to digital photography. They had name recognition, most importantly they had a name that people associated with "photography." They just failed to adapt to the newest trend and died off.

Others have mentioned stores like Kmart, Sears, TWA, and others who were massive but died off because they failed to adapt to market changes. But you can also look at the WWF's rise as an example of driving out competitors who failed to adapt to a changing market. Vince took advantage of cable TV and the homogenization of television to push his product nationwide. No one did that on the scale that he did so they're out of business now.