Dh and I have two ds's. My parents are both in poor health so have never looked after either dc. Dh's parents who are both younger but retired and very active were always really good.
They never did regular childcare as we always used nursery/wrap around care. But they'd have the dc over to stay occasionally and they'd take them out to the park/soft play sometimes on the weekends for a few hours. We all got along well afaiwa. They dc enjoyed it and oil always said they'd been really good.
Dhs sister (sil & her dh) had two dds quite close together. Pil started minding both dds a couple of times a week as-well as collecting them from nursery. I did feel a little bit miffed that this support was never offered to us but of course I would never have said anything.
Pil then started suggesting that our eldest was too old to go out with them to soft play etc on weekends but they would take the younger ones. But there was never an offer to do anything a bit more grown up. Eventually youngest was pushed out too for being too old so Pil stopped taking our dc out at all.
This wasn't a weekly thing it was maybe once every 2-3 months. Not as though we were taking advantage.
A few times we asked if Pil could have the dc over to stay at the weekend but they always said they were too busy but never offered any alternative dates. We'd often find out they were looking after sils dc.
Our dc are 9 and 12 and pil haven't taken them out for probably 2 years now.
In itself that wouldn't bother me, but I know that they mind sils dc a few times a week and take them out regularly.