If this is really the end state of humanity then we should stop all automation and reel things back 10 thousand years or so. This is, modern people can imagine the end of the world before they can imagine a world without money based capitalism.

Go back far enough in history and money disappears. We had barter and trade and happiness still existed without money.

Go back further and trade becomes les important and violence/cooperation to achieve what one wants becomes greater.

Trying to shove money in a post labor world won't make sense and will just lead to war/genocide if we don't find a way to transition.

Barter still exists. It is largely inefficient as we don't see things having equal value. Even in barter, often some intermediate that was a form of money emerged, such as a staple food that could be stored for a relative long term. In smaller communities, there was a bit of not seeking equal exchange because belonging to the community was more important, but that doesn't scale well to larger groups and can lead to some people being taken advantage of and thus leaving the community if that is an option.

Violence is problematic for self evident reasons. Cooperation I already touched on about the community involvement, with all the same problems.

It isn't that we can't imagine a world without money, but that we quickly see the problems with it given the scale of modern day life.

As for post scarcity, it really depends upon what is post scarcity. Money becomes meaningless for things that are not scarce, but some things remain scarce.

Post labour is still resource constrained.

How do you efficiently allocate resources? Especially when you have a wide spectrum of preferences.

I think if you spent long enough thinking about that problem you'd just end up inventing money. You'd have to call it something else so it sounded rebelliously anti-capitalist though