An article at ETF.com agrees that Bitcoin Futures ETFs will make it easier for investors to invest in and manage Bitcoin exposure, however, systemic risk could develop due to an unnatural supply-and-demand imbalance for the Bitcoin Futures themselves. This could occur not only because of the potential popularity of the ETFs from consumers, but also because the ETFs could see huge flows from other funds managed by the issuer of a Bitcoin Futures ETF that could create destabilizing demand shocks.
The article suggests that ETFs that invest directly in Bitcoin itself, rather than via futures, would avoid many of these problems, citing the success of funds in Europe and Canada that hold Bitcoin directly. But so far, the Securities and Exchange Commission (SEC) appears to view the risk to investors of funds investing directly in Bitcoin or other cryptocurrencies (which are largely unregulated) as greater than the risk of funds investing in Bitcoin futures (which are SEC-regulated).
For now, investors seeking crypto exposure through ETFs will have to rely on products based on derivatives, and accept the risks that come with doing so!