Earlier quoted context omitted.
But the BBC don't actually own the rights to most of their old output. They were made in an era too where streaming rights weren't a thing.assume it's different with newer stuff but...
If it is in the publics best interest for the BBC to own the rights then that can be arranged
Is it in the public interest?
What is the benefit to the public of the BBC spending the money necessary to reclaim the rights to their old content? I can't think of anything. The shows that have any value (eg Dr Who) have already commericialized. Everything else ... why bother? The obvious point is that it'd be nice to watch some of the old shows again, but really, out of the 97 years of content across radio and television probably 99.9999% would never be looked ay by anyone.
Just as a parallel, there's millions of hours of old content on https://archive.org/ that never gets looked at. Why would the old BBC content be any different?