It's not even not your keys not our Bitcoin. That would be holding it in your 'coimbase wallet's or similar.
You literally are not buying Bitcoin on any way. You are just buying a fund. Nothing more.
Or he's lying because he's scared someone is going to 5 dollar wrench attack him.
How do you even "transfer" your Bitcoin to ETFs? Don't you have to sell and realize cap gains tax and buy the ETF?
Sounds dumb as fuck.