I'd guess that an AI card should have a great value proposition to be worth buying.
Sure the card should have great value or must have an accessible price. It probably also depends on how "heavy" the tasks get. But seeing e.g. OpenAI struggling with requests, it may be useful to decentralize the processing (with running the model locally on the user's pc).
I'm not sure where you're going with this, but it feels wrong. I'm not buying a hardware part that cannot function without a constant internet connection or regular payment.
Maybe this statement was a bit confusing. What I meant was, that in a transition phase developers could choose to allow the usage of a dedicated accelerator card to run everything locally and offline. And for people who don't have or want such a card they could provide a cloud based subscription model, where the processing is done on remote servers.