I guess the safety issue is up to the buyer to decide. One could also ask, "Is holding your own bitcoin safe?" There are lots of things that can go wrong self-custodying as well. So, to me, it's a personal choice for each individual. I know people who would definitely loose their keys and therefore lose their bitcoin. An ETF would be much safer for them.

I think I do understand what you're saying though...if Coinbase or whomever is actually custodying the BTC gets hacked or there's an inside job or goes belly-up or whatever, that'd be a problem for sure.