Everyone should be familiar with Marx’s essential criticisms of capitalism.
In summary, while constant capital (machines, workhouses, and such) is a necessary factor for production, it produces no profit. Profit only comes from variable capital (labor). With automation, less labor and hence less value goes into each good. Increased productivity means that more use values, but those commodities are cheaper in real value*.
It’s not true that more useful goods means less labor is necessary. In the commodity economy where valorization in the highest aim, there can never be enough work. While socialized production would negate this horrible fact, capitalism always wants more labor to exploit.
Yet, the market compels continual automation to give individual capitalists an edge. This process leads to less and less value going into goods and more and more constant capital compared to variable capital. Even if the gross mass of profit grows (which is what the capitalist cares about), the relative profit from production perpetually decreases. And the problem of too much stuff calls for destruction: planned obsolescence, destruction of goods while people have needs unmet, and, of course, wars.
*with inflation, l monetary wealth increases quantitatively without real wealth increasing
Someone with more theory under their belt can probably articulate it better than me, but I think this stems from a conflation of capital and value. Dividends come from capital you provide to hold shares, and then the company pays out some of its profit. If you were buying those shares directly from the company, they would get that capital to use, but of course unless you're buying an IPO that capital is going to whoever bought the share before you, in that chain back to the company.
But my understanding is value is different - because where did the capital above come from? You were presumably paid it as a wage, which you used to buy the stock. You were paid that wage because you used your labor to generate value, and the value was in surplus to the expenses of the company, generating capital for the company. They paid you some, but not all, of that capital, so that you would keep working.
Bots are a different problem, but you can think of them as embodying the energy used to run them, which eventually leads back to the human labor building the servers and operating the power plants and extracting the fuel. That being said, bots trading capital back and forth like that does not actually produce any value, it's just changing the ownership of the capital that was already produced previously. They generate relative wealth, but not wholly new capital