But how would you know before watching?

“Based on the upvotes and comments” Oh then others doing the work to watch it and rate it on lemmy for you.

Imo, when a link to a video or forum or whatever is posted, then at least a summery or a discussion should be included.

No, you have not understood anything. Assuming Jellyfin would go closed source, (ignoring the GPL license and so on) you would not notice anything. Your server and service would be unchanged by this.

Emby is the best example, the community will fork it and you server lives on. Even if not, then the server and software is still yours.

If it becomes an issue, then you’re in the exact same position you’d be in today if you decided to move away from Plex now.

I disagree. Right now you got time to do the research, plan the move and test it out with a demo setup. You do not know if you got the time if Plex decides to screw their lifetime users.

Yes this is hypothetical.