did Israel express any desire for Hamas to just... surrender?
But Hamas have rejected these calls for surrender.
There was also a recent proposal by Egypt, in which Hamas wouldn't surrender, but would relinquish power in Gaza. Hamas has rejected this weaker proposal as well.
It seems like fighting Israel at this point is a lost cause so I'm confused as to why Hamas won't just give up.
Militarily, it was a lost cause from the start. The massacre of hundreds of civilians wasn't part of a military plan to take over Israel.
The goal was to spread terror, and to force a response from Israel, which can then be used to present themselves as victims of aggression to the world (relying on the fact that general anti-Israel sentiment will result in people quickly forgetting the cause of the war, ie the brutal murder, kidnapping, and torture of civilians).
From the point of view of the leadership of Hamas, they have nothing to gain from surrendering. They are in relative safety, and surrendering would put them in Israeli prisons (at best).
From the point of view of individual Hamas terrorists: They might very well believe what the leadership tells them (that the war is going well). Putting down arms would also not get them closer to their goal of destroying Israel and displacing or murdering all Jews in the levant. "Giving up" from that is not something people do.