I appreciate your passion but the relationship with Israel is more complicated than Biden saying "Israel stop or we can't be friends anymore".
Israel is a strong strategic partner that provides a lot of value to the United States in terms of intelligence and military support, which is not a bridge we want to burn if there are other options.
Aside from that, Israel has a lot of backing from Americans across the political spectrum. Since America isn't a dictatorship Biden has to rely on congress if he wants to get anything done. Since Biden has to rely on congress to get anything done, and Israel has broad support from American voters and thus their Congressional representatives, Biden has to make sure he doesn't piss off congress. So burning diplomatic relations with Israel would probably hurt Biden much more than it would hurt him at this point.
As a last point, a lot of people are advocating for withholding arms sales to Israel. This is the "nuclear option" of diplomacy and once it's executed we don't really have any more leverage. So if the United States stops arms sales to Israel, and they don't stop the invasion of Gaza, we don't really have anymore carrots left to influence Israel.
Our complex relationship with Israel is a problem that the United States needs to solve, but it is incredibly complicated and is something that will take years to sort out effectively.