The Nigerian type scams typically prey on greed; time pressure isn't part of the draw.

There's another class of scams where the draw is fear - "your son is in jail", "your bank account is under investigation and will be closed in 24 hours if you don't act now", &c. They rely on time pressure to prevent the victim from reaching out directly to the parties they're lying about and disproving the scam.

This is aimed at that particular type of scam and that particular type of victim.