but whats the point of a futures ETF?
I think it stems from companies trying to hedge themselves to stay competitive even if market conditions change.
If you bought oil last year for $3/gallon as an electric company and now have to buy it for $6/gallon, instead you could've (as a lot of companies do) estimate how much energy you'll use and either open a futures contract directly with the producer to buy it at say $3.30 a gallon instead for a certain amount of years then you can still offer a good price to your consumers. Most pension firms are also in the market of life insurance too for the same reason.
Every other etf sort of stemmed from that, as well as shares normally needing to be held in the country they're bought (this is referred to as a bond normally though but can be called an etf) or you have to sign a contract with thst country and provide an application for holding the stocks.