Most of the Western world has cheap or free public colleges. To say the plan is ludicrous is kind of dumb. We spend like 50 billion on food stamps, with a similar amount to public schools it would essentially be a minimal burden.
But it’s always someone else*s money - taxpayers pay for it so it’s not free. All those European countries are pretty much socialist and when people talk about how cheap this or that is it’s because they’re heavily taxed. Socialism works until the government runs out of citizens money. Look at Venezuela to see how well that worked.