I think I can relate a little to what you are feeling. We are the "stable" family out of my siblings as well. Not that the others are "unstable" as far as family goes... but one sibling has been married less than 4 years and has no kids, so pretty much do whatever they want on their own schedule and can put all their own needs first, with 2 incomes. The other sibling, has had some financial issues over the years that my parents have helped out with several times (again over a 20 year period), had the first grandkids, and now the youngest grandchild, who also happens to have special needs. My husband and I, on the other hand, have 2 kids that are neither the first nor the youngest grandkids, live the farthest away(my parents moved when I was in college, to be closer to my older siblings who stayed near where they went to college), have a decent retirement plan in place, earn a fairly good income and I am a SAHM. From the outside, things look like they came pretty easily to us. My husband, however, has quite the dysfunctional childhood and miraculously turned out pretty "normal" despite it. Perhaps even, dare I say, because of it---he didn't want that for his family/kids.
Anyway... I finally came to the opinion that my parents get something out of "being there" and "helping them out" with my sibling and his family. They get to feel NEEDED. And not just needed, as in convenient (I mean, I could pay a babysitter if I NEEDED one, but just as a convenience I might choose not to) but really needed-- as in, if mom and dad don't do this/help us, we are sunk. THAT kind of being needed. It can be a real draw to some people to be able to pat themselves on the back for ALLLLLL they've done for someone. Interestingly enough, they always manage to share with US how much they've helped out elsewhere--- never $$ figures, but enough info to make it plain that they REALLY went out on a limb or went out of their way, or whatever....
It took me a little time to figure out how I fed into their sharing the info with us... but now I know how to deflect it when something is about to be shared that they "probably shouldn't be telling you"...
It sucks. But I guess even older parents need their egos stroked sometimes... and being independent doesn't do much for that. It seems to make them feel like WE think we can discard them because we don't need them. (Not true. But I think they THINK that way sometimes).
I also get a lot of "we worked hard when you were young and scrimped and saved so we could enjoy things in retirement" ... when they are justifying a big expensive trip. But when you ask if they want to go out to dinner together to a nice local place (for fresh seafood they can't get where they live).. they suddenly can't afford the slightly better things in life... they "have to stay within their budget". Or if they have seen such and such at the movies, or signed up for Netflix to see movies... "we can't afford to do that"---always with a hint that WE are spending beyond our means or are somehow extremely wealthy and aren't concerned with financial matters.
Blech.