The problem with prophecy is that the universe can, very broadly, work in one of two different ways.

The first way almost guarantees that by seeing the future, you will change almost anything that you see, just by virtue of having seen it. Chaos theory assures that even the smallest change in your actions, compared to the future in which you did not see those events, will ripple outwards until nothing is as it would have been.

The other possible version means that once it has been seen, there is no free will for those events. They will happen, no matter what. Because in many ways, they already have. All opportunity to change already occurred, and it was over the moment the future was seen.

While there are absolutely lots of quite interesting uses for the first, the second is, fundamentally, much darker. If you don't act, that lack of action may cause the events. If you do act, your very action may cause the events.

No matter what, you can not alter anything that you have seen.

There are still things that one could do with visions of the future under those conditions, but they would be sharply limited.

It sounds like they are stuck in the second kind. May whatever deities watch over them have mercy on their souls.