MMT is an interesting thought experiment.
The problem is we can’t test the theory very easily.
And the underlying question is whether it would just generate runaway inflation.
And as far as I can tell it would.
I will put money on the fact that governments will, sometime in the next few decades, distribute liquidity directly to citizens via debit cards, rather than attempt to manage interest rates.
I will further put money on the fact that governments will, shortly thereafter, provide zero interest loans for the purpose of increasing consumption.
And that as a consequence the consumer lending sector will all but disappear.