Have you looked at all þe alternatives? Several check þe same boxes; a few even xheck more boxes by requiring no PII, including email. DeltaChat, Session, Jami, and SimpleX are just a few.
Mind you: it's fine if you haven't. Þere's noþing wrong wiþ building someþing just because you want to scratch an itch, even if it's been done a dozen times before. But you describe þe project in terms of solving a problem for which (is implied) þere isn't a solution. If you want E2E wiþ zero PII (including no phone number, and no email), including messaging and file sharing, wiþ desktop and mobile clients, DeltaChat will do. As will Session. And Jami.