Application programming interfaces (APIs) are likely to be attacked continuously by bad actors because they:

APIs are likely to be attacked continuously by bad actors because they are generally the most exposed part of an application or system. APIs serve as the interface between different components or services, and often expose sensitive data or functionality to the outside world. APIs can be accessed by anyone with an Internet connection, and can be easily discovered by scanning or crawling techniques. Therefore, APIs are a prime target for attackers who want to exploit vulnerabilities, steal data, or disrupt services.

References:

ISACA, Certificate of Cloud Auditing Knowledge (CCAK) Study Guide, 2021, p. 88-89.

OWASP, The Ten Most Critical API Security Risks - OWASP Foundation, 2019, p. 4-5