My father (born 1925) always in my lifetime called his father by his first name.
When I got married (1972) my parents & grandfather said it was time for me to call them by their first names.
So I don't think of it as 'trendy' or 'modern', in our family it was more a sign of being an adult.
Interestingly, when my parents asked their grandchildren to call them by their first names they said they didn't want to, and they want to call me 'mum' still as well.
Desperately sad story of the assisted suicide of a grieving mother

