I have a free trial for Apple TV+ and may check out Foundation. I read the original trilogy about 5 years ago, and it did indeed seem unfilmable to me. I thought the books contained clever ideas and concepts, but they leap through time there is little chance to make a movie out of them.
They could make The Mule into Thanos like character (Avengers) and it could potentially work. Of course, it would be a completely different product on the screen but that is to be expected.
I thought the “thousand time span and the same actor” problem was handled very nicely in Foundation.