That's sorta the problem. No one can buy them, so nobody makes them. End result is that the economy stops functioning, nobody builds anything, and a perma-depression occurs. This can't be a good thing...
As for what stops company B from competing - it's the cost of tooling up all these automation centers and the risk that after all that, your "prey" may itself get better and nobody will buy your product. Microsoft was massively profitable for the 1990s. Google was massively profitable for the 2000s. Why did nobody compete with them? Because if they did, Microsoft/Google would crush them like a bug.
As for what stops company B from competing - it's the cost of tooling up all these automation centers and the risk that after all that, your "prey" may itself get better and nobody will buy your product. Microsoft was massively profitable for the 1990s. Google was massively profitable for the 2000s. Why did nobody compete with them? Because if they did, Microsoft/Google would crush them like a bug.