Any US president will support Israel due to geopolitical relations the US has with Israel: https://en.wikipedia.org/w/index.php?diffonly=true&title=Israel–United_States_relations.

Biden is at least acting as a moderator in the war, which is significantly better than the GOP who are saying they want Israel to “finish the job” when talking about Gaza. Voting third party will benefit the GOP and make the situation much worse.