Disney for years resisted selling films on videos because they had no way of controlling how many people would be in the room watching the content. And they investigated single-use tapes (these had a latch that prevented rewinding, you'd have to send the tape back to the factory to be re-wound) and 24 hour DVDs (these would be sealed in an oxygen free case and would start oxidising on contact with air).
This short time we've had of "owning content" has been an anomaly and it's something they've wanted to stop as soon as possible.
> My Plex server is full of DVDs and BluRays I paid full retail price for (that's $20 to $30 USD each), it's not stealing to use it,
Format-shifting is not legal in all places. It's currently not legal in the UK. And if it requires circumvention of technical measures (which ripping DVDs and BluRays does) it's probably not legal because of DMCA.
If you want to change the law you're going to need a better argument than "I bought it", because you haven't bought it, you've licensed it, and they control the licences.