I have been in this since BBS days and I will tell you what I tell every client: the weakest link is always the human. You can have perfect DKIM, perfect SPF, perfect backups, and someone will still click because the email came at 9 AM on a Monday when they are rushing.
In São Paulo I see this targeting local bank customers more than hosting, but the psychology is identical. Urgency, authority, fear of loss. The only defense is slow down and verify through another channel.