amusing that the studios do all this work in contracts to make sure they have rights as long as they possibly can and then they forget to take care of the physical media
That older content just had no concepts of ever being used for anything other than the original broadcast, or eventually, hopefully, syndicated broadcasts. People survived off of royalties from syndication which is why it was a big deal reach that 100th episode. Once they reached 100, they could phone it in. That's why so many older shows had 20+ episodes per season to get to 100 faster.
times have changed. the quality of home video is so much better than it was, and now people pay attention to those details. compare a 4k HDR with surround to a VHS with maybe HiFi stereo audio tracks played back on most commonly the speakers on the TV itself. The timeline from VHS->DVD->HD->4K is not linear which is something I think a lot of people do not appreciate.