Hamas won’t accept it.

That's a pro not a con. Obviously any international peacekeeping mission's main objective would be to wipe out Hamas completely. The key is to make it easier for Palestinians to support their liberation from that regime that it would be if the - unfortunately necessary - occupying solders were Israeli.

All the other main groups might be willing to negotiate a peace deal. Hamas (and a few smaller similar groups) are what needs to purged to make that happen.