Yet another iteration of this.
I'm in my 60s. I do all my GC's childcare. My choice. I do school drop off, pick up, after school care. I do weekends when shift work requires it. I also do a couple sleep overs a week.
I do it willingly. I love my GC and want to do it for this limited time when they're young. Yes, my DC (parent) is entitled but I'd do it regardless so think not doing it would be counterproductive for me. GC will not be young for long, and I want to make the most of it.
BUT this is what adult children don't seem to understand (not just mine, all the AC on mumsnet wingeing about their parents not doing childcare). People my age still have to work. Our pensions don't kick in until we're 67. So I still work full-time. And to add childcare on top of this is EXHAUSTING. Yes, I know parents are tired too. But the parents are 20-30 years younger than grandparents.
The result of the old people (me!) working AND doing childcare is that ultimately, we are not at our best with our grandchildren. Mine are not getting an enriching experience with me because I'm so tired that I'm there in body only. Yes, I take them places so they can play, but I'm never down on the ground / out in the park participating with them the way I'd like to be. I literally have no energy.
So please bear this in mind, when you want that free childcare. You may not be getting that lovely, nurturing experience for your children. You may get a wrung out dishrag, who can keep them alive, but not keep them happy.