There is a big difference between spending time with a grandchild, and providing childcare for that grandchild. I became a granny for the first time earlier this year, and I love spending time with my granddaughter, though we can't see them that often, because they live a long way from us. We go down as often as we can, and spend as much time with the family as we can, whilst we are there.
But in all honesty, even if we lived close by, I don't think we would be able to offer regular childcare - dh works 3 days a week, and I have long covid and mobility issues, so I'm not sure I could safely care for a young child. We would obviously be available for one-off childcare or emergencies - and when my DIL had to go into hospital, when the baby was only a few weeks old, my dh went down there to help ds1 with looking after the baby, so he could also spend time with DIL.
I do appreciate how difficult it is for young families at the moment - the cost of living crisis, on top of the cost of childcare must be absolutely horrifying, especially if you are only just keeping your heads above water. But it is also hard for grandparents who have raised their own children, and who may not be in particularly great health - and who may be knackered and looking forward to a gentler pace of life as they head towards retirement and beyond.
I don't think it is reasonable to expect/demand that your parents provide childcare for your children - you can ask, and I am sure many grandparents would be happy to help out - but if they can't do it, they have the right to say no.
As regards spending time with your grandchildren - I do agree that it seems sad if grandparents don't want to spend time with their grandchildren - I think they are missing out, and so are their grandchildren.
My parents didn't spend much time with my dses - they lived a long drive away, and had interests that made them want to spend most of their time at home - but I did feel that we were right at the bottom of their list of priorities, and that did hurt. My ILs lived close to us, when we had ds1, and couldn't wait to come and see him when he was born - I think he was only about 4 hours old when they first met him. Obviously I didn't expect my parents to get into the car and drive 5+ hours to meet their new born first grandchild, but I got the definite impression that they weren't bothered about seeing him. I don't think they met any of them when they were babies, and even when they were a bit older, they only saw my parents if we packed up the whole kit and caboodle and went to visit them. It didn't seem to occur to them that, with dh working full time, and the boys in school, it was harder for us to visit them than for them to come to us - dad had taken early retirement before ds1 was born.