you are missing one key aspect: high latency. i am in a rural area with bad internet access. especially bad latency. every request to hackernews for example takes seconds. even if it doesn't make sense for hackernews to be offline. updating new messages, posting replies, upvotes, downvotes. etc, would all work better if they happened in the background, so that i don't have to wait for them.

that's why local first also makes sense for server bound applications. it's not offline first, but by moving online activities into the background, all my interaction with the site would be snappy and smooth, and i could read and comment and move on to the next action without waiting for the browser to reload the page