I think that it absolutely can be a critique on capitalism, specifically hyper-consumerism and whatnot, and I'd argue a lot of shit like 2814 is invoking a cyberpunk-esque theme, which is in itself a critique on capitalism, but I don't think that sells it for the whole genre or anything. I'd argue that the main critiques in the genre are against not capitalism as a whole, but instead against the current state of consumerism specifically. It invokes a certain dreary nostalgia of "look what they took from us," in the bright non-personal advertisements full of people, shopping malls, and places of consumerism that used to have 'character' and be filled with color and designs juxtaposed with our modern-day world of overbearing minimalism and targeted ads specifically about the products.
In general, I think vaporwave is a critique primarily on the aesthetic of capitalism, or more specifically the perceived dying of it.
Another factor I can think of: I watched a video recently about the death of shopping malls, and it talked about the concept of malls not just as consumerist hellscapes to buy-buy-buy, but also as a Third Space for people to exist, as opposed to the First of their home and the Second of their work or school. As a zoomer, I never experienced this, but I imagine the nostalgia of vapor lies not necessarily in the capitalist elements of the things that it so enjoys to indulge in the aesthetics of, but instead what they embodied to people. Malls and retro looking food courts and restaurants were places to hang out with your friends, people aren't nostalgic for buying things. Except in the case of advertisements, where they remind people of when the economy was still doing pretty good and you could buy the things you wanted. But then, things never really were perfect, and you can argue that the slow droning, repetition, and distortion of classic vapor was an attempt to show that this nostalgia is truly "nostalgia for a time that never was."
All in all, short conclusion of my thesis is that vaporwave serves primarily as a criticism of the evolution of Capitalist aesthetics, which through discussion could be extrapolated out to a full critique of capitalism, but I don't see it making any of those bigger-picture arguments in itself, though it can occasionally hint at them.
Overall, though, I'd also like to say that it's heavily artist dependent, I'm sure that there are plenty of hypercaptitalist artists who just genuinely love consumerism.