Palestine or Israel are not illegally occupying land. Israel took control of land when neighboring countries came making an attack on them to annihilate Israel, as any other countries might do.
Because, when attacked by other countries, what you do is invade and annex their territory and keep it forever, and then slowly continue doing that over decades. Because that's totally what happens in that scenario "just like any other country".
Sorry, you're fooling nobody.
Also, I find it fascinating that you apply this logic to Israel, but you would not apply the same logic to Palestine. After-all, Palestine actually IS defending itself from a neighbour that is encroaching on and annexing it's territory and threatening them with genocide. If you think it's justified for a country to occupy territory on the basis of them being attacked from outside, then you should side with Palestine when they fought back against the Israeli invasion, and you would be justifying Palestine invading and annexing Israeli territory in response to their invasion.