Although Israel and Hamas have modified some of their initial demands, their core positions haven’t moved. The two are basking for totally different end-games. Israeli prime minister Benjamin Netanyahu is still fixated on his belief that eliminating Hamas militarily is within the Israeli military’s grasp and is thus reticent to accept any arrangement that leaves Hamas a viable force inside Gaza — even if he gets all the hostages back in the process). Hamas wants a permanent end to the war as soon as possible, not necessarily because they care about Palestinians in Gaza but because they want to save their own lives and ensure the movement lives on. 

That’s the most basic issue hindering a deal — when, or even if, the war will end.