Perhaps a dumb question but why is offline stressed so much here? Nothing in the underlying tech seems to suggest one should expect it to not work offline?
Browser based apps generally struggle to function well offline (this is also true of certain native apps, but that's a whole other discussion). Using the PWA "toolbox" you can have in-browser apps stored locally via service workers so that they work without needing to fetch anything via the internet.
It's rather useful, and can provide a much better user experience, especially when you have a patchy network.
We have a quota on the number of documents you can create, after which you must subscribe. It's a very generous quota, but we still have a good number of people subscribing.
Our major income comes from larger corporate contracts with medium to large businesses, that deploy our product on-prem. Often these were people who used our SaaS product, liked it, and asked us to deploy it internally for their business. Much less hassle than running a company that's purely SaaS based, and more stable income!
Other users have already explained the technical aspect of PWA (i.e. you can install it and run offline as a desktop app). I just want to add that by offline-first I also mean confidentiality -- your data doesn't leave your device, whether you're offline or not.
You need to use specific browser APIs (Service Workers) in order to support "offline mode" for a webpage, including support when there's no internet at all. This means the page and its content is stored locally for later, separately from normal HTTP caching.
Yes, if you loaded the page once into a tab and then never closed it ever again, then it doesn't matter so much and you could use it if your internet shat out, but in practice people close and then re-open things later under varying network conditions.
