Why should passwords never be stored in plaintext?

A breach would expose every user's password directly, and people reuse passwords across many sites.

Real-world consequences:

• Systems get hacked sooner or later
• Plaintext passwords can be directly used
• Users reuse passwords across multiple sites
• One breach compromises many accounts

Example: Knuddels.de was fined 20,000 EUR under GDPR for storing passwords in plaintext.