Why are triggers mainly used for legacy systems?

Triggers in databases are often associated with legacy systems because:

• They are implemented at the database level, which makes support and scaling difficult in modern architectures where business logic is separated into different services.
• Triggers can hide logic, making system behavior less transparent and harder to debug.
• New systems more frequently use explicit calls from code or event mechanisms, which improve control and testability.

Thus, triggers mainly remain in old systems where rewriting logic is difficult or where the architecture was originally built around them.