I'd argue you're conflating two independent axis: technological progress and societal inequality.
AI is useful today and is getting more powerful and efficient. This is obviously great for humanity! It's enabling discoveries that were previously out of reach, and allowing us to accomplish the same amount of work with less effort.
AI is also generating massive amounts of money for the wealthy and powerful and increasing inequality. This is not great for humanity!
I do think it's important to keep in mind that this centralization of power and wealth is not caused by AI directly: the pattern exists whenever there's a desirable but scarce resource. The same argument that AI is increasing inequality can reasonably be made about concrete, steel, and steam engines. The problems caused by AI are really human problems at their core. It's possible AI could even help us fix them! (I'm not at all hopeful.)