YouTube Kids in theory solves all my problems, the issue is that it's garbage software where the most important features are broken. For example I recently went on a long trip and grabbed the kids tablet. Only to discover after leaving the house, that all the previously downloaded videos were gone, and all the new ones that the app had chosen from among my whitelisted channels had "failed to download", despite having been at home on the wifi for weeks, so without internet connectivity, the app had nothing at all.

As others have pointed out, the things I am looking for in a YouTube kids replacement is quite specific and detailed, and the landing page provides not an iota of evidence that I will get that.