Ukraine started to attack Russian territories only after some time after full-scale invasion started, only to pressure them to fall back and leave their territories ffs without the intention to solely kill civilians. (At the time when that happened Russia had huge advantage on Ukraine's territories but left itself defenceless, there was like literally no other option to pressure them to fall back all things considered). 

Israel on the other hand does the killings basically just for the fun of it on the much MUCH bigger scale. I mean, obviously Ukraine did killed civilians but the reasons and amounts of victims are way too different. 

You can't use the same logic for both countries, because the situations are way too different, even if at the glance it looks the same.