The convenience that you provide is not sufficient for me to give you not only access to a significant part of my financial information but nearly unrestricted access to my money. In addition to that, not only do you have access to it but any of the services that you might use. And I probably don't trust them either.
Furthermore, I'm also deeply skeptical of services that require you to top up an account and then use that balance. This is mainly because of the way these types of accounts are (ab)used in South East Asia. (eg. if you top up that account and use that balance to buy something, you wont ever be able to get a refund in money, it'll only ever be refunded to that account) Besides the fact that in many cases you have limited access to your own money.
With that said, given that I'm probably a bit more privacy conscious than an average user given I'm in tech I'm probably not your target market so my feedback might be nearly irrelevant.
Btw when I shared a house, I had an Excel sheet where I put the bills and rent as they came in. A few days before rent was due I'd remind everyone that the sheet has been updated and when everyone paid their share I'd pay all the bills. I definitely understand how your solution could be a selling point if you live with people you don't trust or are unreliable.