AFAICT, the descriptive aspects of MMT are widely accepted, if deemphasized in prescriptive contexts, aspects of mainstream economic theory (not just [neo-]Keynesian, but across essentially the whole spectrum of descriptive economics.) The prescriptions that MMT adherents make based on those descriptive aspects are out of line with mainstream prescriptions, which tend to honor what MMT loudly points out (and mainstream economics more quietly acknowledges) is the fiction of the finite public purse.

Take the very basic thing that you mention at the end, which should be absolutely non-controversial: the US government cannot be forced into default.

If your prescriptions are just going to ignore that fact, then have you truly accepted it? I'd argue that no, you really haven't.

(That doesn't mean you'd have to follow the prescriptions of MMTers necessarily, e.g. the Job Guarantee is certainly not a logically necessary conclusion of the fact that a sovereign government cannot go bankrupt. But your whole framing around government spending and revenue really does need to be centered around this observation, or you're simply bound to fall into fuzzy and incorrect thinking all the time.)

The US government 'can't default' but that is basically word games for a complicated tax where nobody is quite certain who is paying. The government is definitely consuming real resources and unlike a tax it isn't at all obvious who would have gotten those resources had the government not redirected them. I'd rather governments were straightforward and levied taxes to pay for things so we know who is supporting state spending.

The conversation really hinges on the semantics of 'default' - in real terms the Government absolutely can default. At some point the country has collapsed, there is nothing left to give (see classic hyperinflation cases) and the government will not make good on its debts. In nominal terms the government can't default but anyone who treats that as useful in their decision making is going to lose out sooner or later when it comes back to real goods and services. I don't want to be one of those people, and I don't want there to be any people like that because it seems dishonest at some level to pretend they aren't losing out.

People call US bonds 'risk free' - that is only in nominal terms. In real terms they are actually quite risky. Take on a 30 year treasury bond today and there isn't any certainty how much it will be worth in 2020 dollars as it matures. Is it a likely net win on the sandwich scale? Signs point to no, but it might be. There are risks.

The next steps are to recognize and integrate into the conversation that:

* Whether and to what extent the government consumes resources that would otherwise have been consumed by somebody else cannot be determined purely by looking at the deficit as a single number. A government deficit, when done right, stimulates the economy which means that it causes the creation of resources that otherwise simply wouldn't have been created.

* Inflation, which is what you're really getting at, is complicated and has many potential drivers. A government deficit can be one of them, but isn't necessarily. There are many other potential drivers: overly lax monetary policy, excessive bank lending, entirely internal mechanism such as genuine supply shocks, businesses' price hikes in an attempt to increase profits, strong unions helping drive up wages broadly across the economy, and so on. Note that some of these effects, especially the last one, are actually desirable for most people, meaning that inflation can actually be a good thing for society overall! Admittedly that happens rarely in practice, but that's really a function of workers having too little power. It all depends on the details.

In fact, on that last point there's reason to suspect that we'd have had quite a bit lower "effective" inflation (meaning higher purchasing power of wages / salary) for the majority of the population today if governments had decided to address the Global Financial Crisis by direct job creation and handing out money to the population at large, rather than leaning on monetary policy which really only caused asset prices to balloon.

This alternative policy wasn't even discussed seriously, because people largely do not understand that the government cannot default. Discussion was shut down with slogans like "making sure that the US is not going to be the next Greece", which are complete nonsense given that the US and Greek governments operate under very different currency arrangements (sovereign currency like Japan, vs. the effectively foreign currency of the Euro in Greece's case).

So anyway, the point is that the framing in real resources matters significantly, precisely because there is no ironclad correlation between government deficits and real resources. People need to learn to go into the real resources framing and then stay there.

That's a tautological and zero-sum way to look at it

Regarding the 0-sum aspect, I don't know how else you can look at it. Ownership of capital has to follow a certain distribution, which can in turn be more or less egalitarian, depending on how we decide to set the system up. it's however not possible to have both concentrated ownership and co-op style ownership at the same time (for the same company).

Only in the sense of "industry control over government". Which doesn't strike me as any improvement.

The true opposite would be "industry has to fend for itself without being able to co-opt government to tilt the playing field in its favor".

Sure, good point. However I don't think it's possible or desirable to let industry be completely independent of the state. It seems to me that would lead us right back to our current predicament - power would concentrate and it would start putting pressure on the state.

The state itself is a concentration of power. Industry wants to co-opt it for that very reason.

Ideally though, all concentrations of power should be dismantled.

Whatever power you use to reduce concentrations of power would undoubtedly become quite powerful.

I think that it's probably better to attempt to reduce the size of any one concentration of power, and set them all up watching each other.

Agreed. It would be great if power was as decentralised as possible and if individuals would take an active part in their (self-)government.