"Fiat Software" is something you made up.

You can't prove that you're running the unaltered FOSS code you claim to be running. You also can't prove that its a private/secure service and that you're not selling/storing/sharing user data.

I suppose there's a niche for this but as self hosting continues to get easier, your business model makes less and less sense.

Fundamentally, its the same trust model as Gmail, etc. Only you have to pay for it.