I can (obviously) keep my own private keys, but that doesn't get me the tax benefits.
If you invest in Bitcoin, own your private keys, you will only have to pay tax if you sell your bitcoin with profit (higher value than your entry price). If you hold it, no tax or am I wrong?
About Bitcoin ETFs, are they tax free? I did not research about that but I guess no tax free.
Application. I am not an expert in accounting and did not read all the application, but looks like the tax has a chance to be 21%, lower than 30%. Is it what you implied?
If it were treated as a corporation, the Trust would be subject to entity-level U.S. federal income tax (currently at the rate of 21%), plus possible state and/or local taxes, on its net taxable income, and certain distributions made by the Trust to Shareholders would be treated as taxable dividends to the extent of the Trust’s current and accumulated earnings and profits. Any such dividend distributed to a beneficial owner of Shares that is a non-U.S. person for U.S. federal income tax purposes generally would be subject to U.S. federal withholding tax at a rate of 30% (or such lower rate as provided in an applicable tax treaty).
The same applies to any stock market: people are totally used to paying a broker to keep their shares, and the stock market is a lot bigger than Bitcoin. It's a good reason to diversify though, so at least you won't lose everything in case one of them loses everything.
Surely is a thing to do to keep our capital safe with capital diversification. In stock market, cryptocurrency market, ETFs or centralized exchanges (if we store our capital in centralized exchange accounts, not recommended of course). Even with non custodial wallets, diversify capital to different wallet softwares and different wallets are better.