Crucial to Keynesian theory is that profit driven banks who operate with the authority of the central bank to effectively create new fiat every time they provide new finance must only provide finance that can be reasonably expected to increase the overall wealth and prosperity of the economy/nation they are operating in. So if a commercial bank helps finance a new factory or railway or data centre with fiat debt issuance it is reasonable to expect that new business/facility will increase the net productive output of the host economy therefore (probably) offsetting the debasement that increased issuance of money in circulation results in.

If however a commercial bank issues finance for a non productive asset (such as a residential home) and where that finance enables no new productive outputs, then the debasement caused by additional fiat debt issuance (increased volume of money in circulation) is not offset. To allow such fiat monetary issuance would be to ask for trouble- yet that is exactly what the neoliberal deregulation of banking allowed.

In my country the ratio of commercial bank lending to real estate since neoliberal deregulation has grown from below 5% to over 60%. That's 60% of fiat debt issuance now not compensating for the debasement its creates- that is parasitic crony capitalist misuse of fiat monetary leverage delivered to you by neoliberalism.

Previous to neoliberal 'reforms' nearly all housing finance was provided by mutual banks and building societies- where there is no profit motive and no rentseeking incentive to inflate the market as commercial banks have done ever since deregulation.

Keynesian monetary policy kept a lid on housing cost/prices by removing any incentive or ability of bankers to inflate the market - neoliberal deregulation in many economies rapidly transformed homeowners mortgage payments into the largest source of profit for commercial banks- the funding of productive enterprise has shrunk accordingly as commercial banks can provide housing finance at lower risk than (potentially) productive enterprise.

The original justification for the privileged access to fiat debt monetary issuance enjoyed by banks was that they could select and vet potentially productive funding proposals. That pretense flies out the window once you allow them to fund any purpose whether it is potentially productive or not.

Libertarians follow the same 'the free market solves all problems' mantra as the neoliberals did - it is nonsense as there are some cases where markets absolutely need regulation to prevent bad outcomes- cases such as the one regarding banks and the issuance of new fiat money via debt as described above.

While free markets often do provide the ideal outcome this is not always the case and all of this must also be seen within the context of the reality that the nation state and its power projection capacity is a crucial factor in the wealth of nations. There has never been a sustained strong economy without a strong and sustained government that protects the nations interests, projects power to gain access to resources and markets and ensures the rule of law and confidence that provides citizens and businesses.