Genuine question, if everyone now is talking about how we should have known UST wasn't going to work, why didn't we see that before the crash?

I have seen and watched multiple videos recently about how something like Luna/UST was always going to be unsustainable and that 19.5% apy for staking it couldn't work long term.

If all that is so obvious now, why couldn't people see it before the crash? I know people were warning Do Kwon that Luna could be crashed before it happened, but I didn't get any sentiment that people expected that Luna/UST was going to crash/fail eventually. Did people just not want to believe that such a large crypto could fail or was it less obvious that people make it out to seem now?