Currently, we're just using Google Keep, since it at least supports syncing, sharing, and checklists, but I'm hoping to find something more privacy friendly, and/or more feature rich. In particular, what I'm looking for, in order of priority, are as follows:

• Doesn't need to be self-hosted
• Lists that can be shared and synced across users and devices
• Basic Checklist functionality
• Reminders, ideally with options to repeat until complete or similar
• Automation, such as automatically recurring events, esspecially recurring after date of completion
• Private storage of user data, or at least better than Google
• Hierarchy and other sorting methods
• Sync to calendars, ideally Proton