Integrating Jellyfin as a plugin for Kodi will help Kodi lovers access media from Jellyfin server. Cool.
Personally I am not a fan of the interface or all the bugs that happen with Kodi…spending as much time maintaining it as using the software for designed purposes.
What would be AMAZING is a way to have Kodi integrated INTO Jellyfin… so while in Jellyfin you can access Kodi. In addition to the amazing Jellyfin interface and polish, it can be accessed through iOS devices pretty easily where one can not say the same for Kodi.
Would be great to be using Jellyfin, select Kodi and then access Kodi where Jellyfin is the processor and delivery mechanism for content (less so Kodi.)