> How would an offline-first Internet look like?

1Password comes to mind. If you sign up for the subscription, you can easily access it offline, sync to the cloud now or later. Enable 2factor, and you can still access the vault offline, want to sync with the cloud? Enter the 2factor ID and you're in business.

> Your Work Is Not Trapped on One Device

Microsoft Office does a great job with this and office 365. You have the powerful Word running locally, saving both on disk and virtually in the cloud. But then if you switch machines, want to use in the browser? Easy no problem

> Seamless collaboration

Doesn't Git solve this problem?