What is even the benefit to using Oracle JDK at this point? Years ago, I saw that some jetbrains IDEs said to use it instead of openJDK, but I haven't seen anything else like that.

Oracle JDK offers LTS support with regular security patches and critical bug fixes, even for older LTS releases. (More than a decade plus, I believe, but need to check)

OpenJDK community builds usually only provide updates until the next release (6 months).

Oracle offers paid commercial support contracts: guaranteed patch timelines, 24/7 enterprise support, performance issue troubleshooting, and compliance assurance.

You can also built features atop the Oracle JDK and still get support. SAPJVM does this for instance - hot debugging as a feature.