the "let's compare capitalism to existing socialism" line is mostly flawed from the outset because you're usually comparing global south countries to western imperialists who've built their wealth from robbing those places.

you can't compare the UK to Cuba, you're erasing a history of colonialism, warfare, sanctions, slavery, 20th/21st century imperialism, countries trying to build up their economy against a globalized capitalist system, and many other factors

what's interesting is that even cuba, which has suffered under so much imperialist exploitation and pressure, is better than the US on so many metrics (healthcare, higher education, etc.)

one of the reasons foreign policy, or education on the cold war is so important in convincing ppl of socialism is exactly bc of this - to remove the notion that history has developed within each country individually, to give them context when comparing capitalism to socialism

another mistake is to conceive of socialism in europe as smth that will look similar to cuba. cuba has its own history of struggle, socialism in europe or the US will be different, & it will make cuban socialism look different as well bc they wouldn't be isolated & disadvantaged