Is "Not Your Keys, Not Your Coins" Also True for the BlackRock ETF?

Considering switching out Cold Storage BTC by cashing it out and buying the BlackRock BTC ETF.

Why? Well, it seems to be safer. I don't need to worry about self custody. It just chills in the bank account like any regular stock.

I've been holding for many years, I'm not a cypherpunk, but I know my way around crypto, mining, staking, bridges, safety, know probably all the best practices, I'm not at a risk of losing anything.

But still... an ETF in the bank seems like a safer option compared to a hidden USB stick?

The question is serious. BlackRock are a behemoth.

I know that anything can happen, but technically can you actually lose your coins with freaking BlackRock? Is there any insurance that they offer? Not sure.

May be a sin to say this in a Bitcoin sub, but I kinda trust my big bank (and BlackRock) to not lose my assets more than I trust myself, if that makes any sense. And again - I'm savvy, but human. They have systems and fallbacks and whatnot. Also... Insurance?