When parents do something for their adult children, the kids tend to look at it from their point of view that their parent is saying they are still dependent upon them. But it’s usually the parent saying that they are still a parent and are unsure of how to adapt to their children’s new way of being.
And it’s understandable. We are born completely dependent upon our parents / caregivers for everything, we remain this way for almost 2 decades.
Why does your mom always try to feed you when you stop by? Because she’s done it more than 20000 times before.
Why does she not cook food the way you like it? Same reason, she’s been cooking it HER way forever and there’s nothing wrong with the way she cooks it; you’ve changed.
Why does your dad ask about the car and tell you how to maintain it? Because he’s been looking after the car for years and knows how to look after the car his way.
None of what they are doing is saying that you are incompetent, they are just saying they know better (different) and because they’ve gotten you to this point they know their approach works given your comparatively short track record. After 20 years of doing it your way they’ll believe in it; and you’ll probably be fighting with your own kids about it.
I’m not saying that as an adult you should just do what your folks tell you to do, I’m just going to say that their way did work for a long time and it may be all that they know. Remaining open and seeing their attempts to help you as being what they likely are, their way of saying “I love you” and “I’m still your parent.”