The big difference is Ukraine is on the border of NATO, Ukraine is fighting Russia. Russia could end the world in nuclear war, its a non-zero chance. NATO can affect western interests very well in Eastern Europe.

Israel is in the middle east the only “Western” country, and used as a foil for “Western” interests in the region acting as a bulwark against other middle eastern countries. Israel is fighting a group that poses nearly zero threat to world stability. Israel divides middle eastern alliances and can play KSA and Iran off each other.

So the big difference is Ukraine is useful to be the rock upon which the Russian military is destroyed, winning the war isn’t really a western goal. So the west ties the hands of Ukraine in their military aid as the big strategic risk is if the war spreads.

Israel has no restrictions because they need to be a political foil in the area, and none of their neighbors pose a risk to international order.