When you've been subjected to decades of drivel asserting loudly and repeatedly that the reason CEOs get paid big money is specifically because they are the ones who hold the responsibility for screwups like this, you start to think that maybe they should actually be held accountable, just like they say they deserve.

When an individual engineer screws up, if the processes in place are working correctly, that screwup should only cost some time and possibly a bit of money—most likely within an order of magnitude of a few days and $100. This is why we have processes in place: because people are fallible, and it's not good to give any one person that much power.

When a CEO screws up, there's no one to catch that screwup. The buck stops there. So many of these companies are structured specifically to give the CEO some significant degree of autocratic power—the power to say "this is what we will be doing, because I say so", whether or not they have other justifications backing them up—and now that we're saying, "Hey, that kind of power is supposed to come with accountability," you try to tell us they shouldn't?

As for "companies can run fine without one," I'd say that's a very useful hypothesis to test. But your strawman of "give a bunch of money to people on fiverr" isn't the logical way to test it: it's "set up a system with democratic processes in place, create a management committee, possibly with a rotating chairship, and in general give the employees more say over the direction of the company they work for".