I did not say or try to imply that it’s good. I said sadly it works. With emphasis on SADLY.

The thing is: If everyone hated it, it would not work. But sadly it DOES work.

I’m happy with Eternity

DecSync CC is an app that stores calendar / tasks / contacts as files on the phone. You can sync them to other devices. I use it to sync our family calendar and contacts in our household. No clouds involved.