Is it sustainable? 

For me it seems, that people were taught by society to want everything "free". Google drive, facebook, instagram... They don't want to pay with their money for it. They prefer paying with something else.

But on the other hand there is patreon, that also works.

So you think nostr would work because of being a bitcoin patreon? 

 Why do you need patreon ?

I’m personally unable to pay you through that service.

I’m sure there are many whom refuse to sign up. The data leaks are forever and I’m seeing a resurgence in a clean digital footprint and keeping personal information closer to the chest.