The nation state is going the way of the dodo. Either a transnational capitalist class will structure power relations throughout the world, or a global democratic movement will step up and demand justice. Which would you rather see happen?
First, there's plenty of money for everyone to get the benefits that they want. There's absolutely no need to have debates about raising taxes, deficits or MMT. All such arguments are distractions. If we want to pay for things like Medicare for All, Free College, or the Green New Deal, we need look no further than the coffers of the Transnational Corporate Class.