Jellyfin:

• Free
• Gets the job done
• Not in financial trouble
• No layoffs
• Not trying to sell you stuff
• Not selling your watch habbits
• Mainly develops features people want

Plex (paid):

• Decade of development with pretty solid pay features
• Easy sharing with friends and remote watching
• Decent clients for almost every device and more solid transcoding
• Fairly quick fixes for problems
• Great intro/credit/commercial skipping
• Only develops features that might make money
• In the middle of layoffs
• Centralized authentication makes is impossible to watch if offline or they’re offline unless you removed local authentication before it went offline.
• They sell your viewing habbits

Plex is super convenient and slimy

Jellyfin is pure and behind on features, clients and comforts.