I know there'd be a ton of problems, but I do think it's a shame they can't give such actors a week of making a 'film bank', a couple of green screen chats/deaths etc..., partial plot expositions, some running through forests, generic corridors, a few Enterprise/Tardis bridge scenes would give something you could build a moderately complex plot with in ten years time. And if the bank is varied enough you probably should have (even with 70's technology) enough tricks to require a second viewing.
I guess now we have the more disturbing deepfake option, and earlier you film was expensive. In addition to the whole morbid element of it, and the need to plan ahead.