Must preempt this by saying that DP's are late 60s but I don't consider them elderly. Both active, and fairly well, both drive.
My issue is that we never meet up unless it is at my house for dinner. DM will never say to me to come to hers for a coffee even, and has complained about my step sibling calling in without advanced warning, so that makes me feel that I can't just pop in if I'm passing by 
Recently my dc commented that we have never been for dinner at anyone's house, they always come to us and it made me feel a bit sad really. DM will say we really need to meet up, but what she really means is that I have to invite them, and when I say they are welcome anytime (we are very open door policy) they will say OK, we'll come at dinner time.
I don't think this expectation is an age thing, apart from the fact they aren't infirm or anything a lot of my friends still go for Sunday dinners or at least once a month to their parents. I suppose I'm just asking if you still get invited to your parents house for dinner and how often?