The very nature of capitalism facilitates concentrations of power
No. Capitalism is one thing and one thing only: the private ownership of the means of production. The very nature of private ownership, means private citizens have the freedom to own what’s theirs, and trade it with whoever. The nature of capitalism, meaning its logical end state, is a free market in the truest sense. This is the opposite of concentrating power, because the means of power are completely disunited. In less favorable terms, the logical end state of capitalism is anarchy or chaos
Socialism is the common/public/collective ownership of the means of production. Holding the means of power in a collective is another way of saying it’s being concentrated. The logical end of socialism is the concentration of everything.
Of course, I don’t think we need to take either extreme too seriously. They both have faults, clearly, and they both devolve into something that more resembles the other with time. Capitalism adopts regulations or develop a state to concentrate their power against and enemy. Socialism reduces state power when civilians want more freedoms.
Point is, your characterizing of Capitalism seems misinformed, and it’s incredibly silly to think a fundamental replacement of our current system is in order, as if there’s some perfect ideology we can obviously replace it with
the private ownership of the means of production
You recognize how that itself is a concentration of power, right
If you own the source of wealth, you can buy more in a positive feedback loop, thus concentrating wealth and therefore power. Them being private actors means they are accountable to nobody.