Damaged or destroyed facilities included: 

Hospitals, water treatment and sanitation facilities funded by the U.S. Agency for International Development (USAID)

A dozen factories built with USAID money

Dozens of schools operated by the U.S. State Department-backed United Nations Relief and Works Agency for Palestine Refugees in the Near East (UNRWA)

More than a hundred UNRWA facilities were struck, causing more than a million dollars in damage. 

The impact is far more than financial. As The Intercept's Daniel Boguslaw elaborates: 

In Khan Yunis, Rafa, and Beit Lahia, wastewater treatment infrastructure and water reservoirs funded by USAID, which the U.S. government spent millions to construct, were destroyed by aerial attacks that affected more than 300,000 civilians. Ninety-seven percent of the water in Gaza is contaminated, resulting in a widespread public health crisis, rendered even worse by the destruction of U.S.-funded water infrastructure.

The May 2021 war took a steep toll on Gaza, with more than 240 Palestinians killed and nearly 2,000 wounded. Four thousand rocket attacks from Gaza on Israel killed 12.   

Israel's periodic devastation of Gaza is often characterized as "mowing the grass." Yoav Galant, a former Israeli military commander, embraced the philosophy in a radio interview: "This sort of maintenance needs to be carried out from time to time, perhaps even more often."