On iOS, Dropbox integrates with the Files app. Since that was added a couple of years ago, I rarely have to open the Dropbox app itself. About the only time is when I want to restore an earlier version of a file.
You can also mark complete folders as “Make Available Offline”, which will keep their contents updated, though I don’t really use that personally.
The biggest benefit of the ios dropbox app is to search through the contents of all files. When accessing from the files app that is not possible, unfortunately.