I was on a full grant for uni (back when that was nearly enough to scrape by) and borrowed money from the bank to cover the shortfall. I probably got about 400 a year from my parents on top, but I was mainly funded by the state.
We borrowed a deposit from my PiL. (5K, but it was decades ago!) which we paid back over 5 years.
Once we had kids PiL babysat once a fortnight for years so we could go out, didn't really save us much money as such, we just wouldn't have gone out if they hadn't offered. If we'd lived closer I think they would have been happy to babysit more, they provided a lot of childcare for SiL.
After uni my mother became disabled and was no longer capable of providing any assistance. My father gave us 5K, a few years after buying the house, when we got married (again, decades ago!). But other than that, he doesn't help out at all (and we've never lived close).
If I was growing up today, I don't think I could have gone to the uni I did and I don't think my PiL would have been able to lend us enough for a deposit on a house where we were living. So I'm not sure how useful that is in thinking about how much parents help out. I got through what are traditionally some of the poorer years in much cheaper times so it was easier for parents to have a bigger impact.