I use Apple Reminders on my desktop, but the Apple Reminders app is fairly basic and doesn't support things like subtasks or tags. And unfortunately the app abandoned the CalDAV protocol in iOS 13/macOS 10.15
Technically the Apple Reminders app can still be used with third party CalDAV servers, and third party clients can still synchronize with iCloud, but icloud.com, icloud.com list sharing, and Apple Reminders with your Apple account on iOS 13/macOS 10.15 now use a proprietary protocol.
Technically the Apple Reminders app can still be used with third party CalDAV servers, and third party clients can still synchronize with iCloud, but icloud.com, icloud.com list sharing, and Apple Reminders with your Apple account on iOS 13/macOS 10.15 now use a proprietary protocol.