Investors gain exposure to Bitcoin "without the need to buy, hold, and store Bitcoin directly, avoiding the complexity of crypto exchanges and wallets" and lose ownership and control over their very own funds, as a result.
In this way, they gained exposure by getting numbers instead of the real thing. They avoided the complexities of custodial wallets and gained the complexities of traditional financial products.
This is essentially moving backward rather than forward.
It's all about who do you give your custody to - you either keep it safe by your side or sell off to those wanting to have your funds on their side, even if you think you still control them, you don't.