I have not read any of the books, which I think might be an advantage in this case. Movies and series often have a hard time living up to the books.

I got into reading Game of Thrones because of the books. The part of the series I saw after I read the books always came across as lesser than the parts I watched before I read the books.

I understand why the Foundation TV series could not be a faithful adaption of the books though. TV almost by definition has to be quite character focused. The quality of actors have major impact on how you perceive a TV series or a movie. Thus I think changing the story was required. Whether they made sensibel choices is another question.

Dune seems better suited for film adaption with its more iconic characters. Yet I did not find it very interesting to watch. No interesting acting or dialog I could spot. No interesting ideas.

I suspect Dune may look good on the big screen though.