There is no rule in capitalism that says you have to optimize for capital accumulation over any other goal. There is not even an evaluation function, people can choose their own values.
Just listen to all the people kicking and screaming that interest rates should be increased or that 0% interest rates are wrong and negative interest rates (which represent decentralization of capital) shouldn't even exist. There are consumer protection offices advocating that accounts shouldn't be charged negative interest rates even though it only applies to accounts with more than 100k€ in checking accounts. Imagine the horror of getting a certificate of deposit for one whole month. Instead, some banks have decided to just charge monthly fees which is incredibly regressive because you would need 25k€ in your account to exceed the monthly fee at -0.5%. Meanwhile if you have millions on your account you pay the same fee, ah yes, subsidize the rich.
And nothing in capitalism says you have to value buying a yacht higher than anything else. There is also no rule that says capitalism should have no laws whatsoever.
Power is also a good thing, for example being able to cure cancer or feed people is a power.
Power is something you have over another person, ie the ability to violate their preferences. That's an inherent negative. Presumably the power to cure cancer is something the patient would consent to, and thus not the kind of power I'm talking about.
Capitalism has led to the kind of voluntary transactions where child slaves are paid just enough to not starve so that mining companies can extract cobalt to sell to electronics manufacturers. While the idea of voluntary transactions sounds nice in the small, it plays out pretty badly writ large.
As for wealthy people being not natural, as I said, usually you become wealthy by giving people something they want or need. That is the best thing to reward in a society.
What do you mean by "natural power imbalances", like somebody having more muscles than others? Then why can't you imagine that some are better businessmen than others, too? Was Steve Jobs just an evil guy becoming rich by exploiting his employees, or did he become rich because he made the world a better place for billions of people? Would the world have been better if Steve Jobs had been shot down at an early stage to give somebody else a "fair chance" in his place?
Marxism wasn't a success story in the real world, either.
Now, that was never going to happen, because of the iron law of bureaucracy - states only ever consolidate their own power so Lenin's plan was doomed from the start. But the USSR was never socialist.
I'm not sure what you think is impossible about socialism, because if we were to legally replace corporations with cooperatives, which is not a huge jump in terms of economic law, that would be market socialism. Its happened before (briefly in the USSR before the consolidation of the bolsheviks in power for example, for example in the meaning of the word "soviet" itself) and cooperatives work perfectly well as an industrial unit.
Coops based on voluntary participation are entirely compatible with capitalism, you can already set up a coop today in capitalist countries. Socialism is not voluntary, it forces everybody to participate. It is the most exploitative system, because everybody is supposed to only work for the common good, not for themselves. It also sets the wrong incentives which is why it usually ends in misery.