The Palestinians did not have a proper military system, an army, hardware, technological research, satellites, let alone a valid state or government 75 years ago. They were basically sheep herders and farmers. Any nation or people who do not have a valid army system, an air force, a navy and a valid governmental system are open to conquest. This is what happened to the Palestinians/Irish/Kurds and other nations or people defeated in the past or in the present.
The infrastructure of any nation requires a valid defence force or military deterrent, and the Palestinians never had this in 1948. Instead, they relied on guerilla warfare or terrorism to attack their enemies.
In Gaza today, the Palestinians are ruled over by a Hamas dictatorship who use the people they oversee as human shields/cannon fodder/collateral damage. Instead of building infrastructure for the people they dictate over, Hamas uses the billions of UN/EU foreign aid to build tin-pot dumb fire rockets, tunnels for smuggling and American weapons acquired from Afghanistan after Joe Biden deserted the country, leaving billions of dollars of hard weaponry to the Taliban. Hamas is also additionally funded and armed by Iran, who advise the terrorist group on spreading terror and mayhem in the region.
Ukraine is another example of a nation that was ripe for exploitation because they did not have a valid army, air force or navy. When they were first invaded by Russia in 2014, they did not have a valid military deterrent. Instead of pouring resources into building up a valid military, they did not spend, and this is why Putin continued his invasion of Ukraine in 2022. Russia was emboldened by the lack of military of Ukraine and the dependence on NATO, which may falter in the future. Ukraine is thus totally dependent on military aid from elsewhere, and to be dependent on others is not a valid deterrent for the defence of any nation.
In essence, without a military deterrent, any people who occupy a land should be prepared to lose that land eventually. Nations with legitimate governments and military have a right of conquest in war and gain territory because they made the effort to prepare. Don’t hate the player — hate the game.