The USSR lasted for 70 years, so that's like 3 generations. It also saved the world from Nazism, eliminated illiteracy, ended famines, became a world superpower, and made it to outer space, all within that time.

But we both know that’s not why it collapsed.

okay, then tell us why you think it collapsed? These vague insinuations and gesturing don't prove your point, they make it seem like you're unsure of the basis of your own assertions.

Edit: And for the record, the first ever experiment of a modern socialist country in history, with no earlier examples to work off of, succumbing to a series of both external and internal contradictions doesn't say anything concretely about the viability of socialism as a whole. In fact, their massively successful strides toward constructing new relations of society, and the betterment of living standards for the vast masses of its people, and the provided security of housing, employment, nutrition, community, and healthcare which was established after fully collectivizing and industrializing (industrializing in 1/10 of the time it took the west to industrialize, without the fundamental basis of primitive accumulation through global colonialism, settler-colonialism, genocide, chattel slavery, child labor, aggressive wars, and malthusian sanitation practices that under-girded the western industrial revolution; and doing so after suffering such destruction in WWI and the civil and counter-revolutionary-interventionist war no less) proves there are extremely strong cases for it being a model of success to learn from and build off of, while learning from its shortcomings and mistakes.

The USA was and remains the richest, most powerful country in history, and responsible for most of the overthrows, coups, and mass killings in the 20th century.