Im not as familiar with Venezuela but the first 3 you listed massively increased the quality of life for their citizens versus how it was pre revolution. Cuba today is still a massive achievement considering the embargo. Just like capitalism didn’t achieve its optimal form when it first came to being, socialism hasn’t been perfect either but we learn from past mistakes and strive for something better than thinking that the current system that only benefits the global north at the expense of the global south is somehow the peak of how human society can be.