I would willingly hold a reputed altcoin instead of holding Bitcoin ETF. Those who are holding ETF don't really know that they aren't holding any Bitcoin and those people are paying fees for holding those ETFs. I would most probably consider holding an altcoin instead of holding that ETF.
In long term it's much safe and better to hold Bitcoin not Bitcoin ETF. However, because those ETFs can be useful for Bitcoin community as the ETF companies will spend money for advertising of Bitcoin, and only because of that I think ETFs should exist.
It's someone own choice to rather hold Bitcoin or Bitcoin ETF and I'm among those people who will Hold Bitcoin or a good altcoin instead of holding Bitcoin ETF. Others might have differing opinion and ideas about those ETFs but for me they're only good because they are promoting Bitcoin for us, nothing else than that.
It's your choice, but I find holding altcoins to be much riskier than investing in a bitcoin ETF. You won't own real bitcoin if you invest in a bitcoin ETF, but you will be protected by law and regulation if you run into problems during your investment. But if you hold altcoins, you will not receive any protection from legal authorities if the project turns out to be a scam. There are many altcoins on the market that are considered very reputable and reputable, but there is no 100% guarantee that they are safe and will never turn out to be scams. Altcoin and bitcoin ETFs, I still think bitcoin ETFs are safer.