On thing we are learning, I guess due to the fact our grandkids stretch out from the ages of newborn to 15, the older they get the less likely it will be you will be seeing as much of them. A 17 year old is not going to spend most of their weekend at grandma and grandpas house, and if they do you should be concerned.
I suspect there will be folks out there that put off doing things later in life because they are so focused on their grandkids. Then later, when their grandkids are starting their own families/careers and are extremely busy, it will be too late to take off and do all the things they should have done while in their 60's.
There is no "right" or "wrong" answer here. Everyone and every family is different.