2 Apple ID's, Can't set up Family Sharing

Way more than a decade ago, I had an apple ID that was used for everything, including purchases. For a specific reason, I had to create a new Apple ID, and Apple would not transfer my purchases to that new ID. So I had to leave the old ID for purchases, and my new ID is signed in when going into settings, to sign in on the device.

A VERY long time ago, the advise was to allow family to share music, have them sign into subscriptions/Media purchases under my old ID. Then somewhere along the way Apple Family was introduced. But when I try to set up Family, I get an message that another account (the old purchases account) is used by another family and can't be shared until the "other family" stops using it. It will not go farther to let me invite family members.

This whole process is screwed up and completely NOT intuitive. Is the ONLY way for my wife to see music or TV/Movies we've purchased over the past 15+ years to login using MY old Apple ID?