Israel and Ukraine are democracies. Russia is not, and no elections have been held in Gaza or the West Bank since 2006.
Russia is the one who initiated the violence against Ukraine. All of Israel's operations in Gaza and the West Bank in the last decade have started in response to deadly attacks carried out and coordinated by Palestinians (The kidnapping of the 3 teenagers in 2014, the riots in 2021 and of course October 7th).
Israel is a small nation. Its soldiers are safeguarding civilians who often live within walking distance from outbreaks of violence. Russia, on the other hand, is a massive country invading another massive country. Civilians in Russia do not face daily threats of violence from terrorist groups in Ukraine.
Israel's operation against Hamas aims to neutralize terrorists and ensure the safety of its citizens, while Russia's invasion of Ukraine seeks to overthrow the Ukrainian government and strip the country of its independence.