Is that really your takeaway from Homage to Catalonia?
The lesson that I take is the silliness of thinking that your political perspective has absolute validity. All of the leftist factions resisting fascism in Spain were doing something heroic. Meanwhile, in the USSR, other leftists were acting as tyrants. The USSR used its influence in Spain to declare various factions illegal (including POUM, the faction that Orwell was aligned with). The Soviets insisted on the absolute validity of their perspective and started persecuting anyone who was skeptical of Stalin in the midst of a civil war against fascists.
> Those given just enough improvements to their own material conditions no longer saw themselves as exploited by capitalism and largely ignored the working classes.
Yeah, it's almost as if human beings care about concrete, meaningful changes that affect their lives and not some all-encompassing, abstract class struggle.
edit - It's interesting that, in the linked article, Orwell says that Franco's victory was not due to disunity but rather the fact that the fascists were well-supplied (by the Italians and Germans) whereas the republicans had much less assistance.