I'm assuming the others are actual banks that are required to...

I'm assuming the others are actual banks that are required to keep a high asset value to maintain savings accounts. My understanding is that Douugh isn't a genuine Neo Bank in that it isn't, nor is it a subsidiary of, bank that receives deposits for savings funds (ie an Authorised Deposit Taking institution). If that is true, they certainly won't require the same level of cash assets in their current account.

If so we would need to ask what they need more than $6M which is a good amount to develop an app and full stack infrastructure and to cover marketing costs and overheads.

Given the company is new, but also the model is unique, it would make sense to "earn the right" before getting access to more money. That is to say they should have enough money to demonstrate the business model works. That they can build something, it's attractive, it's functional, and it earns revenue. And if this is proven in the US market, there should be no need for capital raising I would hope. The biggest test is getting into the US, which they have done successfully. We now need to see what the market response is.

Personally I've always been very bad at marketing. I think Douugh are doing well in this regard and the fruits will be borne over the next 3 months.