Socialism, communism, conservatism, liberalism, all the established political movements have a theory or philosophy of what goals they want to achieve, yes, but also what means they can use to achieve them. They have an economic or social theory.
Populism doesn’t, so all it tries to do is address the symptoms, not the causes. People are poor, let’s give them money. Problem solved! Foreign goods are cheaper than ours, let’s slap an import tax on them to make them more expensive. Problem solved!
The trouble is the reasons why people are trapped in poverty, or why local manufacturing isn’t competitive are not addressed, and populist tactics make those causes much harder to tackle.
The Italian governments policies will, if carried through, impoverish Italy for a generation. Just look at Greece to see what massive debt driven overspending can do to a country. The idea that growth will lift you out of the hole is a fantasy because the factors holding down growth aren’t being faced.