Kbase Article of the Week: If You Get a Message That PowerPC Applications Are No Longer Supported on Your Mac »

Apple Support:

If you try to open a PowerPC-based application, you might see a message that you can’t open the application because PowerPC applications are no longer supported. You might also see a prohibitory sign over the icon of the application in the Finder.

Contact the maker of the application for a version that is compatible with your macOS version.

In a few years, we can just swap all instances of “PowerPC” in this document with “Intel.”