I'm trying to see if Skype on an android tablet (with an appropriate home screen e.g. "BIG Launcher") could be of some use for non-tech savy elderly with poor eyesight.
But the answer as far as I can tell is no because the UI is way too detailed and complicated. It must be possible to propose an interface that has large fonts and only a few big buttons: e.g. one button per contact with a clear ID picture and an answer and hangup button. The process of calling and being called has to be simplified to the max. (see also https://www.noisolation.com/nl/komp/ or https://bbrain.eu/en/ or https://www.konnekt.com.au/)