Libertarianism is mostly interested in freedom FROM the state.

Freedom from the state, to me, implies anarchy. I interperet your wording to say that a libertarian would want the freedom to opt out of governence -- this makes little to no sense. It is true in that a citizen should certainly have the freedom to emigrate, but I'm not convinced that this is what you were implying.

And freedom from oligarchs of all stripes. Especially the ones inherent to all forms of capitalism. Of which “free market” is the worst about.

Why do you argue that the free market will always result in an oligarchy? I will say that a wholly unregulated free market will result in rampant anti-competitive behaviour which will end up being at the expense of the consumer. So, by that logic, some regulation is certainly necessary to ensure fair competition. This sort of well functioning free market should be the antidote to an oligarchy, unless the public wills it to be so.

Capitalism is inherently incompatible with libertarianism

I would argue that capitalism is founded upon the ideals of libertarianism.

In the fact that you realistically can’t choose not to be part of it.

You can choose to not participate in the free market -- create your own local commune where you all freely share your own private goods.

Under capitalism those of us that are not born into oligarchy or happened to luck into oligarchy end up basically slaves to the oligarchs for our wages and basic survival.

Again, no one is forcing you to play a part in the capitalist system. You could grab a farm out in the middle of nowhere, completely off the grid and live off of your own goods (assuming you have some means to cover a theoretical minimum of property tax). That is, of course, unless you are advocating for socialism in that the government should be providing for you.