Kavita is at the moment, aimed to be more like Plex. Theoretically you could upload files, but the main aim is exploring and consuming your content. Different people have very different schemes for where files should go.

One user does everything by genres, so /comics/romance/series, another does it by publisher and years. The problem with uploading is that there is no right answer. It's better to just inform Kavita that new files are on the disk and let the scan pick them up than try to build a complicated solution that is going to meet everyone's niche needs.