Infuse is a better Plex app than Plex is; and it supports Jellyfin and a bunch of other data sources.
It is, IMHO, a platonic ideal of what a “tv-shaped” video player app should be.
Ideally, this would be designed in two parts: separate the file structure from the metadata discovery mechanism.
I personally want a file structure managed by the OS. Let me make folders and nested subfolders to whatever structure I prefer.
Then make the metadata discovery slightly more manual. Click a media file, click a hypothetical "add metadata" button, and then a simple search box with "is this your movie?" and click apply to import metadata from a search result. easy peasy.
The UI is clearly meant to resemble a typical media app but falls short if the end user prefers, for example, foobar2000's UI.
It seems to be tolerating whatever semi-organized structure I give it until it just faceplants on some specific show and I have to tediously reorganize the directory structure/names and manual refresh until the metadata lines up correctly.
I like that I don't feel I'm about to be rugpulled on Jellyfin and the client is pretty solid for me but the library scanning is pretty aggravating at times.