You (and your providers) will not only know my spending but who I share a house/utilities/services with. And personally I place quite a high value on that data (as do others who trade it)
I've seen quite a few companies that operate in this financial intermediary space and start off with strong privacy ideals, and then when they're getting traction and are raising a Series A/B can't resist adding a cool $5-10M ARR with near zero marginal cost by selling out.
Additionally, the fact that it's a "VC-backed startup" is irrelevant. Any company with any structure could be doing this.
Which would make the service too expensive for me.
I don't use Facebook for the same reason.
But as I mentioned in the top level comment, this is a concern for me because I'm probably more privacy-conscious then an average user so I might not be exactly the type of user they're building for.
My previous 2 apartments I lived in required paying rent by paper check, delivered to their office, which was very annoying. They didn't take any forms of electronic payment, and mailing a check is a pain for millenials like me who don't usually stock envelopes or stamps. However, they also didn't take checks written by anyone other than the leasee, so that could be something that might need to be negotiated.
I would drop that whole page, honestly. It’s written in a pretty technical way and didn’t make me feel any safer, and on top of that made me feel like you all were deflecting from the bigger and more immediate threat, data selling.
In terms of your privacy concerns, while we've worked really hard to make our service secure and leverage trusted security storage providers, we know there'll still be some people who are not ok with sharing their bill account credentials. This is why we are very excited to be developing the YSplit card. You can essentially get a card and use it to split & pay the bills without handing over any account details. There'll be some limitations, most notably not seeing all your bill data in one place, but the splitting feature will work the same.