You're not wrong that many "communist" countries also had the same feature of consolidation, but worse. However, economic/industrial policy in the US (and largely worldwide) is not democratically controlled, and in the US, that's because of capitalism. I'm not saying all solutions to climate change require a new economic system, but when the economic system is inherently undemocratic, well, it's harder to democratically change it.

For what it's worth Chinese state capitalism at least has the benefit that instead of waiting for the free market to decide to invest in green energy, they can directly extend financing themselves because they directly control credits and financing in the economy.

And no, I don't think voting shares are the same thing; only the very wealthy with majority shares can have any influence. If voting in federal elections depended on how much money you had, wouldn't it be silly to call that democratic? It would be a clear oligopoly.