I'm indebted to Skype because of the hours I spent talking from Texas to Ireland to a fellow budding author. Many, many hours over a few years. However, I'm getting a lot of crashes while using Skype that need a full restart and reload of Skype. Not quite exclusive to Skype, but almost. It's a @$^@$#%^$ nuisance.
For telephoning, 6 quid a month used to give me the US, where a phone is a phone, on your desk or in yer pocket, but in the UK, Skype would not call a mobile. I now pay a couple of quid to dial land-lines in the UK, though mostly because I need headphones on my PC. Basic cyber-video calling, is, and always was, free.
I don't like What'sApp. I don't know why, but I can't make simple calls with it. If it's on my phone lists, it'll work on my PC, but try as I may, I can't seem to simply dial a new person from my PC. I fear it might be ageing neurons rather than motherboards.