True. But your jellyfish instance only really works for you and a few trusted friends/neighbors. I would still like a comprehensive library that I can browse and select from at a moment's notice.
The infuriating nature of Amazon / Hollywood / IP law / etc, is that these two combined goals are inimicable to the profit motive. I can't have access to a big public library of continent, because that means someone else won't be able to collect the real-time maximal market-rate from me to access it.
Shit happens. Tech breaks. You forget where you leave things. People outside your social circle (people you'll never know existed) will want access to that same media at some future date. And Jellyfin doesn't get them that.