Performance Metrics are not limited to campaigns; they can also be available in other contexts, such as ad groups, individual ads, or account-level dashboards, depending on the platform you're using. However, the exact availability of performance data can vary by platform or tool.
For example, in Google Ads, detailed performance metrics are available not just for campaigns but also at the ad group and ad level. Similarly, tools like Facebook Ads Manager provide metrics for campaigns, ad sets, and individual ads.