It would really depend on where you will buy the "bitcoin" from but you need to remember that you do not actually own the bitcoin you will buy but instead just a representative or a reflection of the real bitcoin. The "bitcoin" you will buy is regulated by an authority and therefore you do not actually have full access nor control over it which is to me not safe since I would want to be the one to hold my actual bitcoin.
If you want to buy bitcoin, let's buy it on a Bitcoin exchange or cryptocurrency exchange. Like imagine of a demand for buying stocks on a Bitcoin or cryptocurrency exchange, see something wrong here?
Buying shares of Bitcoin Spot ETF is risky because these shares have to be backed equivalently by bitcoin. You have to trust the ETF share issuers and their custodians like Coinbase. If anything is shady, wrong with either the issuer or the custodian, you won't be able to claim your bitcoin from ETF shares.
May I ask why buy in stock exchange though??? Why not just buy in a crypto exchange if you really want a centralized authority holding your coin
I agree with you on this.
Want stocks? Buy them on stock exchanges.
Want Bitcoin? As said, buy it on either Bitcoin or cryptocurrency exchange, which can be either CEX or DEX.
Bitcoin Q&A: Not your Keys, Not your Coins