Usually austerity is coupled with drastic reductions in expenditures, both for infrastructure and things like social welfare. This kind of stuff regularly drives ruling parties out of power and leads to protest and revolt.

Not a good choice if you can avoid it!

The problem with austerity is that most countries implemented it were forced into doing it and, due to the particulars of that political relationship, chosen to cut social services instead of cutting cronyism, which is also politically calculated to cause as much pain as possible for the poor and create an unpopular sentiment against austerity and coerce the entity imposing the austerity into ending it.