Deposits are an asset AND a liability
> This means banks in the modern sense can literally create money, so they don’t need your deposits
Not really. Banks still have to spend central banking money when doing interbank settlements, and deposits are an important source of funding to day-to-day operations.
Say you have an account within Chase and want to send money to your friend at JPMorgan, Chase can't simply "create dollars" - they need to have enough reserves in their Central Bank account.
As a thought experiment, if you started a bank from 0, how do you pay out the first loan?
Yes, they create money, but deposits are a requirement to do it. (Unless you are doing some interest rate arbitrage by getting a loan from another source)
Deposits, although an important source of funding are not a requirement, capital is. There are capital requirements that make starting and running a bank a fairly expensive enterprise - you need to put up a lot of your own money (equity) for use.