In an ideal world the status quo in Taiwan would be maintained indefinitely and nobody would make any provocative moves, there would be no war in Ukraine, the Scots and Catalan would amicably negotiate their independence, and the indigenous peoples of North America would exercise meaningful sovereignty over their ancestral lands. There's a long way to go between where we are and that ideal world, and lots of obstacles and problems in between. It's complicated, and I don't have any good ideas for how to get from here to there. To conclude that we should give up on the ideal, though, seems like just learned helplessness and defeatism.
I understand better now the bit about the parent saying their child should be a communist as a youth, but not when they get older. It's not a matter of right or wrong, the parent is just exasperated that their child, after decades of living through the world as it is and maybe frustration that it's not changing nearly as quickly or as much as they want, still believes that we should or can try to seriously change things.
But these are all matters of [differences of] opinion.