The simplest answer is that alot of people would like to hold BTC in a tax advantaged account and an ETF wrapper is the easiest way to do this.

Others would like to buy it via retirement plans and having an ETF makes this doable.

Those that want to hold BTC incase the US dollar collapses will hodl their own BTC.

Those that want to hold BTC incase it really appreciates will hold it via an ETF in a tax advantaged account so they don't have to pay taxes on their gains, depending on the account type.

> Why does BTC need an ETF at all, doesn’t that defeat the purpose of owning one’s own wallets? Also… exchanges defeating the purpose of decentralization…

Many financial institutions do not care about decentralization, but they do care about investing in an asset where they do not have to worry about managing the asset (in that regard, similar to REITs). Having the asset insured against various types of malfeasance is also a requirement for investments by many institutional funds.

Many foreign-currency ETFs exist. Euros, or yen, or dollars can function as currencies even though some people also view them as investments.

Commodities are similar. People might invest in pork bellies even if they don't personally eat bacon.

Your question is absolutely appropriate, as the original vision was not to have care about dollar values and instead use BTC as money.

But now the speculators have taken over, and all that really matters is what BTC is worth in dollars.

>Total US retirement assets were $36.7 trillion as of June 30, 2023, up 3.1 percent from March 31, 2023. Retirement assets accounted for 31 percent of all household financial assets in the United States at the end of June 2023.

I don't think experience shows most people should or want to own their own wallets. And transactions are much easier without owning one. If you just want BTC exposure as an investment an ETF is much better.

The purpose of decentralization was defeated a long time ago, I'm afraid.