In my experience, a slow connection can be less usable for some apps than none at all.
If there’s no connection or you’re in airplane mode, some apps will let you access locally stored/cached data, but as soon as there’s a bad connection, they’ll wipe that data by trying to unsuccessfully refresh it from the server.
If there’s no connection or you’re in airplane mode, some apps will let you access locally stored/cached data, but as soon as there’s a bad connection, they’ll wipe that data by trying to unsuccessfully refresh it from the server.