What is the difference between paying for plex to stream your own video from yourown hardware and paying to use microsoft word to write your own letter which also runs on your own hardware?
As a more serious response - The last time I purchased MS office (decade+ ago) I paid once for a product license I could use forever. That felt fair - I buy a tool, I use it.
Plex had that payment model and got a lot less pushback from the community - but this whole "we're a SaaS now!" thing is just not going to fly.
I just don't trust the company anymore, and Jellyfin is absolutely great.