Re: "Nothing can go wrong with this"
Agreed, but non-cloud based managers trump all - see KeePass with mobile app, where you store an encrypted file on your own flavour of cloud storage.
If your cloud storage credentials are exposed, your password file is still (hopefully) encrypted with other more complex credentials. Also targeted attacks would have to break two authentication walls, one being 2FA cloud to get to your passwords.
Why trust one login to a single cloud provider with all your logins seems nuts to me.