Information has since been reported by more objective parties that shows damage more in line with smaller explosives (so this is probably true), but the US lacks credibility on the conflict because no one sees them as a neutral (or even heavily biased) third party willing to challenge Israel. When Biden says he’s “with Israel 100%” and tells diplomats not to call for restraint, that immediately makes the US government just another arm of the messaging war. There is a cost for stating up front you’re all-in on one side.
Similarly, if Israel had a better track record of not lying about their attacks, people would be more willing to believe them when they say “it wasn’t us”. Going all-in all the time may yield short term gain in whatever current media cycle they’re in, but it destroys their credibility in the long term. And since there have been periodic terrorist attacks followed by brutal military responses for my entire lifetime, they probably should have been thinking in the long term.