I don’t think there’s any one reason. In the early web days there were no client-side data stores, just server middleware and database that did all the work, g

I don’t think there’s any one reason. In the early web days there were no client-side data stores, just server middleware and database that did all the work, generated and updated web pages with a little bit of JavaScript on them. It wasn’t until Web2.0 and iPhone that web and mobile began to have the ability to do the write local then sync model. But the old client-server model was still easier to develop for, had the momentum, and internet speeds were fast enough. Nowadays there are services like Firebase that make it super fast and easy to develop full-featured apps. They provide everything an app needs - user accounts, sessions, data store, etc. All of which is still more work to replicate in the local first model. Afaik there’s nothing like Firebase for local-first.