The fundamental take-away here is that old systems die, whether proponents of the old system believe it's possible or not. I think parallels can be drawn between a lot of articles written by people so deeply embedded in the status quo they literally can't fathom their pet concept might go away at some point in the future. And sure enough, this one is written by a venture capitalist.
Of course, a post-scarcity world is inherently incomprehensible to people who are economists, in much the same way a rational world motivated by ethics is incomprehensible to a religious person. The first sign of this is vocabulary, they'll insist on a "post scarcity economy" or a "religion of science" respectively. While it's probably true that there will always be aspects of supply and demand, and it's likely also true that people will always believe in certain ideas, it's really questionable if these terms as they're being used still mean anything.
These word choices are a subconscious expression of the perceived impossibility of an idea. For example, a world with (almost) no manual labor. Or a world where things are so abundant that for practical purposes of daily life there is no shortage of supply.
When looking at Star Trek it's first and foremost important to keep in mind that these are stories intended to entertain. As such it's moot to try and incorporate every episode of every show into some kind of big common canon. The issue is not whether "Federation Credits" (must) exist, the trick here is to look at the broader concept presented.
There are scientific indications that the general idea of the Star Trek "economy" is valid. When a civilization gets access to advanced robotics, the ability to mine entire star systems for resources, and advanced 3d printers, it generates a setting that pretty much speaks for itself. The interesting aspect here is that this state of affairs is very likely in the cards for humanity's future.
Of course, there are extremely strong aspects of our society still prominent in Star Trek. This is grossly unrealistic, but probably necessary for storytelling purposes. For example, DS9 was really out of touch with the in-universe realities of manufacturing and labor, but it made for some pretty awesome stories.
I believe in the future we have a choice to make when it comes to scarcity, and the battle lines are already drawn today. People who are invested in the status quo will not only tell everyone it's impossible but they will go to great lengths in keeping scarcity alive. Artificial scarcity perpetrated by big powerful players is already a big staple in today's system, and that's only going to get more audacious with growing technical capabilities. I think a good argument could be made that this will lead to horrific social and economic pathologies, and it probably already has.
The big reason the alternatives are scary to a lot of people is not just because they fear a loss of traditional values and social cohesion. It's scary to them because this kind of future is inherently experimental and so far doesn't seem to yield itself to planning from on-high. This means there will most likely be a huge loss of power and influence in the turmoils ahead and it's going to be very difficult to port existing power structures to that new kind of society.
Whether this fundamental transformation is even stoppable in the long run is an open question. There are certainly scenarios imaginable where we just stagnate instead of moving on. It's also not inconceivable that the human civilization might fracture and split up into different groups pursuing their own trajectories - and at least one of them might elect to keep scarcity alive indefinitely.