That only works if:
1. the grandparents are retired and not as busy as the parents.
2. the grandparents are willing and physically able to spend hours each days educating their grandchildren, after already spending hours a day educating their children when they were younger.
3 the grandparents even live anywhere near the children.
It's not a grandparent's responsibility to educate the grandchildren, when there are healthy and able parents already in the picture. It's the parent's responsibility. Grandparents already made raising their children their priority, and are now preparing to retire, and do all the things they couldn't do when their children were young.. Most people look forward to retiring so they can travel and do all the things they had to put on hold to raise their own children. To ask them to now put their senior lives on hold to raise their grandchildren, when their parents are perfectly able, to do so, is a bit selfish of the parents to even ask, in my opinion. If a parent is too busy to educate their own children, then that is their choice and they need consider reprioritizing their lives to make their children a priority over whatever else has them too busy to be a parent.