Things like hospitals, airlines, 911, should have multiple systems with different software stacks and independent backends running in-parallel, so that when one infra goes down they can switch to another.
For some areas of our critical systems we have three independent software groups program the same exact system on different infrastructure. Just for moments like these...
There is an enormous cost associated with the kind of redundancy you're talking about. Capitalism prevents us from being set up in the way you're describing. Why invest in company A if company B can run the same business with half the operational expenses? Shareholder profit above all.
Is company B allowed to take the full brunt of all the problems when there is a failure, or does government protect it by limiting damages? If company B's cheaper choice leads to harm and lets people and estates sue company B into the ground, then company A is a safer investment even if it has lower returns. If government interaction limits such recovery options, then that is what leads to company B's higher returns not also having higher risks, so they'll be the better investment. But that is a result of government intervention, not the economic system in play.