Yeah. Investors buy their shares; they use the money from the sales to buy more Bitcoin, I guess. If Bitcoin's price goes up, the shares will have a higher value, and if it drops, the price of the shares will also drop. I have never been into stocks much, so I don't understand how things really work, but I guess those who have been into traditional financial markets for years would find these things beneficial for them. Someone like me or you who is more into Bitcoin would definitely prefer buying Bitcoin instead of going through such a route.
They do, @freedomgo already answered this for you.
Additionally, you can get all the details about the project, including its holdings, performance, policies, and everything else, from https://www.ishares.com/us/products/333011/ishares-bitcoin-trust-etf
This is a positive development for some and a negative development for others; it's a subjective matter because different people would see this differently. Those who are against regulations and are already tired of the centralized financial markets and how they control their money and investments would never choose to invest in such things. Just buy Bitcoin and keep them in a non-custodial wallet and no one even needs to know about it. Sell it whenever you want without disclosing how much profit you have made.