The Typeform LITE mobile application is built by using CouchDB and PouchDB which means when the application is online, it replicates the users db locally so the performance is great but the even bigger benefit is that when the application is offline, the user can still do the majority of the operations which would be synced once the application goes online again.

So, probably no-one wants to replicate the whole database locally but there is a strong benefit to replicate parts of it for performance and offline-capabilities.

Disclaimer: I was one of two developers on the mobile app mentioned above.