F-droid is amazing. I just discovered it myself and am almost reconsidering my "Talking Senior Citizen's Flip Phone" or at least no longer dreading unpaid phone tech support chores for my family. Have you considered Replicant?
https://www.replicant.us/ There is also LinneageOS: https://lineageos.org/ which I believe is a fork of the now defunct CyanogenMod: https://en.wikipedia.org/wiki/CyanogenMod The best solution, of course, is a landline, but if that isn't possible, the people who are working to make "less bad" Android software absolutely deserve our support. Thank you for posting.
