The Western proletarians are still beneficiaries of imperial superprofits from a multitude of avenues even despite their struggles at times. Most people in the West aren't actively cheering for imperialism, they just simply allow it to continue because they, on some level, refuse to educate themselves on where it all comes from or have fully drank the capitalist kool aid. Their material conditions define them, and their material conditions tell them that their state is supreme. To the average paycheck-to-paycheck worker in an imperial core country, they get given things—often referred to as 'treats'—like universal healthcare, infrastructure investments, full bellies, time off from work, a 'dignified' national identity, things that they know other nations don't have. They never question why people don't have them, whether it be because of their own prejudices or because of pure ignorance.
To the average Western worker, when struggle and austerity hits, it is a failure of the state to not allocate enough imperial superprofits to their needs. The state and its bureaucracy is all they know, and they know it keeps them fed and clothed, so they try to force concessions through it. When the older generation tell them of times that 'things were better' and say 'this country has gone to shit,' they literally observe the fact that the bourgeoisie have rescinded their concessions because they no longer feel threatened, but never internalize it. The bourgeois-proletariat has only ever known the state and understood the state. They don't see the bourgeoisie taking back what they gave, but rather they see the state as being incompetent at resource allocation or otherwise corrupt because they do not understand that the state itself is a tool used to oppress them. Mamdanites and Bernie Bros in the US are an example of this. They never question how the USA became the wealthiest, most opulent nation on the planet, they simply desire that that wealth be distributed amongst Americans as opposed to amongst the proletarian class.