We're foreign expats living in the US, and our parents, who live in Europe, were never involved in our children's care. Frankly no one in our circle of friends benefited from grandparent help with childcare, even our American friends, usually because they were too far (and some who were elderly, medically frail or had already passed away).
Eldercare for parents who are far away, whether here or abroad, is always incredibly challenging. My husband sends money and relies on his local siblings to help with his elderly mother. There is enough money to pay for aides who come to her home, and all the aides are supervised by my husband's older brother. I'm an only child and have no idea what will happen when the time comes: my parents are prickly and likely won't be happy with people coming into their house to help. I pray they're independent for a long, long time. My best friend, whose MIL lives in NYC, recently persuaded her to pay for assisted living in the DC area so they can supervise her more closely.