system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: What would have happened that is so bad if we didn't bail out the banks?
gpt
The concern was something like a repeat of the Great Depression.

It's worth noting that 'bailing out the banks' was a bunch of different things that were done, and some of them might have had more impact than others.   Similarly, there are alternative possible responses to the crisis - like massive government deficit spending.