In a lot of cases crash report SDKs are open source?

Sentry: https://github.com/getsentry/sentry-java Bugsnag: https://github.com/bugsnag/bugsnag-android Exceptionless: https://github.com/exceptionless/opentelemetry-dotnet Rollbar: https://github.com/rollbar/rollbar-apple Raygun: https://github.com/MindscapeHQ/raygun4android

To just name a few.