For sure take your time and please let me know if you have any questions.

(1) So most Traditional Finance investors are used to having custodians. Like just the idea of having a wallet where they could lose the keys or it could get their keys stolen just freaks them out.

For people who live in countries where they can't "trust" governments or financial institutions to protect their wealth, cold storage might make sense. But in the "West," even if a big broker goes bankrupt, the government typically bails the broker out and protects people's assets; this happened (for the most part) after the financial crisis of 2008.

(2) Another reason people like the Spot Bitcoin ETFs in the US in particular is most brokers do not have trading fees. So you can buy and sell a Spot Bitcoin ETF and not have any trading fees.

The big con, that @antisocialist pointed out below is this is 3rd party risk. So there is a non zero chance the custodian gets hacked or god forbid the government goes crazy and starts confiscating people's Bitcoin.

Sorry this comment is so long I tried to make it concise but I am pretty tired. I think will go get some rest now lol.