unfortunately it seems like people have forgotten that we are talking about bitcoin. a decentralized thing that was created so that we don't need banks, government, SEC, ETF, and all their centralization. it is funny that now we are getting excited about centralized entities entering bitcoin market and discuss whether bitcoin goes down if they decide not to enter!
It is true that the idea was at the beginning just like you say, but it is obvious that
BTC can hardly progress if it is not regulated at the level of governments, states and the whole world. Let's say that nothing has been done in terms of regulation, what would be at this point with
BTC? Maybe exchanges would not exist neither crypto ATMs or any store would accept it as a means of payment.
Can we succeed with idea of decentralized cryptocurrency in such a way that we somehow circumvent all existing laws, to not pay tax and to remain anonymous? Probably it is possible, but in that case
BTC would probably be limited to dark web or as payment between individuals who want to trade some goods beyond the existing financial system.
ETF is just simplified way for investing in
BTC intended especially to people who have money, but they do not want or do not know how to handle with buying/selling/storing of
BTC.