My fault entirely. I guess my argument would be that those other corporations also shouldn’t be creating password managers, at least ‘within their ecosystem’.

I believe a password database should preferably be stored locally, and at least in a cloud that is completely separate from your essential account(s) (i.e Proton, Google, Microsoft accounts, etc.) I have no doubt Proton’s implementation is secure, but I think the principle of using it is not ideal.