> "To verify you have a HN account (membership) today, a service provider need to build something like keybase. That is complicated and will be different for each service."
No, they need at-best a small subset of what OAuth offers. OAuth is already distributed in that sense. It's a standard protocol which accounts for this exact scenario. This is a solved problem today.
It's not different than "login with Google"/"login with Apple".
> "You need some way to pay for membership without a middleman. This is solved by cryptocurrency part of the blockchain these nfts are stored on."
What does this sentence even mean? Your membership costs are on a per-service basis, and they are tied to each service you want to pay for. Different services have different costs.
This could make some sense if services wanted to get paid with Bitcoin, but ironically enough - the Bitcoin must be converted to USD at some point down the chain?
> "Memberships are also more complicated than a list of email addresses. They can be transferred, expired, and change depending on the action of the user."
Sure, but wtf does the blockchain have anything to do with this? You're free to have an account with any service and manage it as you wish on an individual per-service basis.