How do you think that makes the cliff less high?
Not bailing out the banks during 2008 would have been austerity. It would also have made things probably twice as bad (2008 was bad, but the 30s were way worse, like 30% unemployment bad)
There is no actual logical path between austerity and improved short or midterm economic performance. It’s feel good politics, simple and easy to understand but also plain wrong
Where do they get that money to spend?
Money spent by individuals and companies is usually better spent than that by the government. (given a law-abiding high trust society)
Money that passes through government is not magically imbued with some extra quality. More the opposite. Remember that story about it being cheaper to hire a taxi than go by train for two or passengers in Greece? That the Greek train system had more employees than passengers and lost a billion per year?
https://www.bbc.com/news/world-europe-16834815
Of course I don't want to go overboard here; money spent wisely by the government on the public good can be more effectively (productively) than the individual or company.
In your analogy, it only pushed the cliff further away. The cliff is still there, it's still as steep and still as high and we will still, inevitably, fall off it and suffer the consequences.
"We" (I'm Greek) as in those of us who haven't yet crashed- haven't yet been rendered homeless, or forced to live hand-to-mouth, supported by soup kitchens and community handouts and so on.
In other words you're saying the exact opposite of what conventional economics says here - massive levels of borrow and spend is exactly why the Greek economy is so bad, and austerity on an equally massive scale is the only long term solution. When the Greek state is a smaller proportion of the economy, actual growth can occur.
Someone who has won IOCCC four times and who was the General Secretary of Information Systems at the Greek Ministry of Finance has got to be worth listening to.
Austerity brings the cliff closer and reduces it's height.
You'll notice the fall and blame austerity but it's better than the alternative.