The fact is that I typically make films on commission so once I'm done, I have been compensated for my work and it becomes the property of the client.
That sounds like a good way of working, as long as you have stable clients.
But I'm conflicted about your words about films being perishable goods. We've seen how art can be rediscovered much later and given a valuable second life - i.e. the films of Buster Keaton and the music of J.S. Bach. New artists are constantly inspired by their predecessors. And in animation, the rediscovery of Lotte Reiniger
's work provided inspiration for modern directors such as Michel Ocelot.
Also, speaking personally, many or most of the films I love (including in animation) were made before I was born. I'd be losing a lot if I had been unable to see them. They are closer to me than most modern movies I see.
I can definitely see how your technique has improved over the years, and I see the benefit of avoiding "competition against yourself" when you're paid by-the-film and not by royalties from past films. All the same, I do hope that more of your films become more widely available eventually
, because they tell worthy, human stories... and people never really change much.