Put a cap on company size. No organisation can be worth more than (say) a few hundred million. You can still make big and complex things but it'll have to be several small(er) companies working in concert, which is already kind of how massive companies work internally anyway. Less efficient, maybe, but I am not entirely convinced that huge companies hoovering up any attempt at competition leads to efficiencies in the long run. And the more value that can be extracted by smaller players, the more that ends up in the hands of humans rather than pooling R the top. Maybe have a credit for capital outlay so building and operating a factory is better than building a financial war chest, and a credit for non-executive salaries so paying your workers increases your company's headroom.
Capital gains tax that increases progressively with gains, and decreases progressively with duration i.e. incentivize significant investors to create long term value instead of chasing quick exits.
