What interests me is that it makes sense to start a “bank” that will take care of customers like traditional banks do. Opening an account, buying a crypt, maintaining a computer, etc.?
For the bank it makes sense. It can even use cypto as a fractional reserve asset, since many customers may just deposit there for long time.
For the crypto user - it depends on the user. Many don't care about "not your keys, not your coins" and if a small APY is offered some will be happy.
Many other users will be outraged, since crypto is meant to avoid third party. Many will prefer to remain anonymous and will keep their coins on their own wallet.
So, it depends on the user.
But.. in order to do this "you" have to
1. Get to get trusted. Big time. No sane person deposits money just like that.
2. "You" have to have all the credentials of a financial institution, accepted in all the countries this service is offered in. Basically "you" have to be a bank with some extra competences.
3. "You" have to ask for KYC from users, which will most probably scare off a big number of the potential customers.
Nowadays banks started making deals with crypto exchanges so they, together, can offer something pretty much close to what you are saying.
