My PILs are like this. my dh and I had our children in our twenties, and the PILs disapproved of our choices. Fair enough, although we were married and both working (things that are important to them).
They have never helped us in any way. No babysitting, no gifts of money, nothing. We've never expected it, but in the early days when we were struggling for money it would have been appreciated. They are very well off, several rental properties, luxurious holidays etc etc. My parents are much less well off but bought school shoes occasionally, bought nice birthday presents etc.
PILs never gave any Xmas pressies to us adults, and charity shop gifts for the dcs. Their choices of course, we never asked for help and it was never offered. Two years ago I gave up work after a breakdown. They see this as weakness, so more disapproval. We live within our means and don't need or ask for help. Just as well!
Dh's 2 siblings had children much later than us, this is approved of and PILs have made this clear to us.
Now PILs are starting to give away some of their money, mostly to avoid IHT. They are in their late eighties and admit they have far more money than they could ever spend, even if they needed residential care.
They have set up regular direct debits to DH's siblings 'to help out while they have small children'. Our dcs are now young adults so we 'don't need it'. To be honest, if they gave us money now, we would give it to our children anyway. They are starting out, struggling to run a car to get to work, or struggling with housing costs. We help them as much as we can but now I'm not working it's hard.
I find it hard not to resent PILs, especially as we live closest to them and are expected to help them in practical ways (cleaning, helping with shopping etc). We do help of course, but I'd do it more willingly if I felt more warmly towards them. They don't see that they have been unfair at all.
We've managed, maybe it's been good for us to manage alone, but they have forfeited a loving relationship with their son and his family, and for the sake of a little forethought and kindness. I couldn't do that to my children.