Greetings from the toliet. I'm looking for something like jellyfin for video games where I could look at the art of the game and see the description and download the game through the web portal.
Reading the description I'm pretty sure it doesn't. Just like Jellyfin it looks it your harddrive for games, adds metadata and gives you a cool interface.
Playnite might be what you're looking for. I love it personally. Open source, the maintainer's a boss and updates constantly, lots of extensions. Works beautifully with emulators too.
Note that this isn't like something that lets you play your games from anywhere or download your games from anywhere.
I've found it to be very bloated and slow myself. Not to mention it wasn't able to detect a good chunk of my library. The fact that it requires an app from the Windows Store is super odd too.
GOG Galaxy is also a really good game manager. I was pleasantly surprised by its newer release. Scans games from all of your popular platforms (Steam, Epic, etc) as well as custom library folders.
To note: it's been having problems syncing with Steam for awhile now, and only workaround is to download a custom plugin from GitHub and overwrite the existing plugin and then hope the one guy maintains it forever...until GOG fixes it of course