Sure, you can try it charge subscriptions, but what are you actually charging for? You're not storing any of the customer's data or providing a service that they need, since the software should work entirely without your help. Fundamentally charging a subscription without having a centralized server is pretty tricky. Even the traditional desktop apps that transitioned to the cloud, like Photoshop or Maya, have really worked hard to beef up their cloud-based service to justify the subscription fee. A mismatch between your business model and your technical infrastructure is not going to stand up well over time. Don't get me wrong. I'm just trying to figure out what business model works for local-first software?