I see no much or other benefit of the bitcoin ETF aside from the fact that it legitimizes bitcoin in the USA and the rest of the world, and I think a simple proof to this is my country, Nigeria.
Bitcoin and cryptocurrency transactions was banned by the previous government, and when the new government came in, the ban on bitcoin and cryptocurrency transaction remained effective until the US sec approved the bitcoin spot ETF, then the government in Nigeria unbanned or lifted the ban on bitcoin and crypto transactions in general.
So, if not anything else, the ETF approval have help make bitcoin more legitimate than it previous was in the eyes of the government, most especially those who don't fully understand it, and going forward, I think good money wil be coming into bitcoin as investments in the future, due to the door the ETF approval has opened for bitcoin and cryptocurrencies in general.