If you don't look both ways when you cross the road, then you may get hit by a car. The solution is to pay attention.
It's acceptable to build a system where human error can lead to catastrophic consequences, even death. Every time you go outside you encounter many of these systems.
Not everything in life can be made 100% safe, but that's no reason to stop living.
Swindlers work by that is a story as old as time. Even snakeoil salesmen were good at distracting people from obvious signs of false promises and warnings. People often overestimate their own capabilities greatly, same as there are no bad drivers on the road when you ask people about themselves.
There are definitely things you could do to improve it though. E.g. you can't activate "I know what I'm doing" mode while on the phone or for 1 hour after a phone call. Someone else suggested a one-day cooldown.
Also for the specific scam they mentioned, why do apps even have permission to intercept all notifications?? Just fix that!
> why do apps even have permission to intercept all notifications?? Just fix that!
I fear "fixing" it would mean removing the feature entirely, which breaks many workflows. Primarily this is used for accessibility (and is controlled in the accessibility settings), but applications such as KDE Connect also make good use of it.