At the end of Tenet, Ives breaks the algorithm into three parts and splits them between the three of them. Again Neil gives his part back to the protagonist before joining Ives, while Ives takes away his part with him. Any reason behind why Neil didn't take his part with him? And what happened to the part of Ives and the protagonist? Were they destroyed later or hidden?
If it was so important to keep the parts of the algorithm apart and well hidden, then why they didn't destroy the algorithm. I have seen this question and other discussion sites where they say that the future generation can go back in time and stop the destruction of algorithm. Well if that is true, then they can go back to prevent the protagonist from saving the world also, isn't it logical? Everything the protagonist do can be stopped by the future generation.
So what do they do to secure the parts of the algorithm? Is it possible to keep it safe at all?