In 2018, around 848 billion (848,000,000,000) emails were sent in Germany alone.
A good half of these were spam mails, but it was still a considerable number. If you then consider the fact that most of them are sent unencrypted, it is actually a disaster how carelessly we (especially in Germany) handle our data.
Because standard e-mails are basically to be regarded as a postcard as far as security is concerned. What does that mean that anyone with the appropriate technical know-how can intercept and read them.