I've always believed that the simplest explanation for any observation is most often the correct one. The fact is we are in and moving deeper into an inflationary period that will last at the minimum for several years.
In times of inflation investors want to have their money in hard assets, as these prove to be hedges against inflation. For smart investors, commodities have always been a refuge in times of inflation. So it is little wonder that we see commodity prices rising. Naturally, speculation is part and parcel of this trend. It could also be true that there is a confluence of a particularly lax regulatory environment under the present US administration and dispersion of commodity trading among wider ranging markets than in the past. All of this together, coupled with some increase in commodity consumption nicely explains what we are seeing as an increase in commodity demand. It is difficult to accurately break out all of these demand components, but surely that portion attributable to the threat of inflation is major.
P.S. Note: some in this forum are using the word "demand" to mean consumption, whereas in the markets consumption is only one component of demand.
If you are a long-term investor, in my opinion you should be holding commodities as a hedge against inflation and should be expecting the current inflationary period to continue for a minimum of several years, and possibly a decade or more.