There are a number of people who are perplexed. And that leads to a lot of speculation. There is also seems to be a strong survivor bias in economic reporting so everyone wants to be on record as both foretelling doom and not-doom, then depending on what happens they hope you'll remember they were "right".
Either way, there are interesting questions here which are unanswered. Like why do companies have so much money in their cash accounts? Generally, if a company is accumulating cash it isn't re-investing to grow. And while that might mean a planned acquisition of some other company the phenomena has gone on long enough that this seems less likely [1]. So why the cash hoard? For people it might be a 'rainy day' fund but does anyone believe that these companies will sit there, paying salaries, while selling few goods, waiting for the demand to return?
Or is it that the rent seeking transactions have become such a burden that it has been completely damping out new demand? One of the interesting thoughts is that if you go back and fix copyright and patents such that their terms expire in a more reasonable amount of time, or in the case of patents they are carefully scruitinized, then you take away this rent stream from big content and a number of license funded entities, that forces them to go out and make new content, or come up with new patented things, rather than just collect license fees. That creates new economic activity and that boosts GDP. It is a point of view that is gaining some adherents as a drag on economic growth.
Shipping as a leading indicator though has a couple of problems, both with isolating improvements in the industry (supermax ships) and shifts in modalities (air freight being acceptable for high margin goods like iphones) and generally the way consumption and manufacturing is changing (China's economic growth has zero impact on shipping if they pulling their bulk goods in over land and shipping locally).
Mostly though I suspect that there are lots of things that are unprecedented and so folks who are trying to plan are in a world of hurt in terms of confidence in their predictions. And like the reference to the movie in the article, it is always safer to predict doom and then report on "avoiding" it, than to mis-predict non-doom and to have it land at your feet. Hence more and more economists are saying "The world economy is toast!" rather than "I wonder if this is what it looks like at the leading edge of the switch away from a scarcity economy?" Sure, we could be approaching the singularity/jackpot what have you, but if you say that and the instead you get the biggest economic depression ever, well that is a worse outcome for the predictors.
[1] In an related note, having 10s of billions of dollars in cash means a company can do dozens of "10 - 50M" acquihire type deals, and that is driving some of the seed investing thinking I believe.