Unfortunately what humanity always found out is that physics always progress. That means that we are always at mercy of uknown physics laws or put it simply: Till now humanity had a lot of luck and everyone luck at some point ends.

There's a big difference between dying because the negentropy finally ran out, after billions of years in the height of life's power in thr universe, and being snuffed out by something as banal as biological malfunction after the blink of an eye.

If nothing else, if I got bored after x number of centuries, I'd want any useful/meaningful memories of mine to be indexed and saved on hyper-wikipedia rather than just be burned because a piece of meat rotted.