IMHO after the Russia-Ukraine war, Russia must pay reparations to rebuild the parts of Ukraine it damaged/destroyed.
IMHO after Hamas is destroyed, Israel must pay reparations to rebuild the parts of Gaza it damaged/destroyed.
In a war, it is fair to damage enemy infrastructure, but you are on the hook to rebuild it once the war is over.
There is a lot of precedent.
Germany had to pay reparations under the Treaty of Versailles, and again after WW2.
The US would have had to pay for Hiroshima/Nagasaki except that Japan waived it under the Treaty of San Francisco.