An ETF to help ease of entry for more people (e.g. in retirement accounts, brokerages etc) will go a long way to helping people purchase bitcoin and take part in any future gains.
ETF's are great, but even if they are backed by the underlying asset, which the Vaneck & SolidX ETF is, people still don't own anything but a promise that for every share that they buy, a custodian has X number of coins in their reserve. It's fantastic for those looking to gain exposure to Bitcoin through a non hassle way, but I would always recommend people to buy and store Bitcoin themselves offline.
You only need a sub $100 hardware wallet to store millions or even billions worth of Bitcoin in a convenient and safe manner. It's small and therefore easy to hide, unlike physical Gold where most people store it in bank vaults because they don't want to have it in their house. Good luck gaining access to your Gold after 5PM during business days or in the weekends.
I agree, it is always best to own one's coins by controlling the private key, but realistically I know that grandparents or older aunts and uncles are not going to do so. So it is preferable to own shares in an insured, monitored ETF vs a fly-by-night exchange with poor security.