I think it's worth bearing in mind people were of their time and the prevailing conditions they lived through would have shaped them in some way. Grandparents of our demographic have almost certainly lived through one if not two world wars, similarly our parents would have been involved or affected by the 2nd WW.
Whilst I might have thought some of their expectations in behaviour overly fussy at the time, in retrospect having spent time in research on Ancestry I realise now perhaps where they were coming from. In many ways I wish I had more conversations about their growing up experiences when they were alive, it never occurred to me to do so. When I was very young I think I presumed that they just arrived in the world as an elderly people
I think I, like many of my generation, I am pretty relaxed around my own grandchildren, I'm just pleased when they say please and thank you, which they do. On the downside when they stay with us, I wish they'd read more books and spend less time of their tables, but that's generational me coming out, books were my main source of entertainment so I would say that! However, they do say, they read more during the week when they aren't allowed to have their gadgetry, only at week ends allegedly, and it's the week ends when we see them.