> Shouldn't the goal be to create a bank ecosystem that is more robust?

You are seeing the robustness in the actions taken by the FDIC right now. Not all failure modes can be prevented ahead of time. There is no failure-proof banking system structure.

> So that the failure of one does not lead to a domino reaction of failures?

The "domino effect" in the context of bank runs is a result of human psychology, specifically herd panic behavior - not something that can be changed by the financial system. At best it can be tempered.

Maybe people should have the option to save their money in a bank that doesn't loan out their savings at all? Does such a thing exist? I would be willing to pay a flat monthly fee to keep my money in a bank and use their services in lieu of receiving their paltry interest on my savings account, in exchange for the knowledge that they actually have my money. I know this system of massive loan-to-deposit ratios is conducive to economic growth, nevertheless I get the impression we're all being scammed on a fundamental level by the banking system at large- and any suggestion of meaningful change is always dismissed as if this house of cards is just the way things have to be, and always has been

According to some comments here, such a narrow bank was proposed, but was denied license by the Fed, which apparently even fought in court to uphold the denial.