I've been hosting Jellyfin on my Radxa Rock-5C for a year or so, and it's done a very good job at it.

The only difficulties that I've faced (mostly in the beginning) were:

• It was a pain to install the drivers for hardware transcoding on armbian. I solved it by switching to some other distribution that's maintained by a single guy. Ubuntu-Rockchip or something. That might have changed since then, but if it didn't you'll probably face it with any RK3588-based SBC.
• It's a bit temperamental in terms of power delivery. Make sure to use a charger with the right USB PD spec to power it, and use a USB hub with its own charger to plug your storage. That's probably specific to the Radxa boards though.

So it takes a bit of work to make it work properly. If you don't want to deal with that, I second some other comment that I saw: get an Intel NUC, the setup should be much simpler. If you don't mind using AliExpress, you can find a brand new one for less than 100€.