There are already a few bitcoin etfs out.
If you are in Canada there is a spot Bitcoin etf since 2021.
In Europe there was a bitcoin etf for a few years already.
In USA you can buy the bitcoin future etf called Bito which was also out since 2021. And prior to that we had the bitcoin futures which is a little harder for the retail market to access.
Ok. In theory, bitcoin etf can be purchased (in some jurisdictions). The question is different. Why do this? Just so that your possession of bitcoin etf is within the legal framework? People must understand that bitcoin etf is not bitcoin, but its surrogate without the advantages of bitcoin, but with disadvantages of centralization.