I feel like this is not true in regards to older material. Shows like wkrp in Cincinnati can never be made available with all of the music liceasing issues. Some classic shows like soap get censored. Some shows just go missing. Most never make it to streaming and many aren't available for purchasing.

Piracy is just as important. The reason why more don't is because it is easier to just pay and perhaps the content is not worth the effort anymore. People watch movies on fast forward now, play games on phones while watching and generally tv or movie viewing as a background activity.