Lama Ole’s answer:
In some respects, there comes a time when one has to admit that they are “ready for the museum.” On some points they won’t be able to change and will just stay with the views and expressions of their time. In those cases, keep talking to them in a way they can understand and which benefits them. Try to keep things they can’t understand at all away from them, because for them it is now about enjoying a happy old age. You can tell yourself, “I can’t change them anyway, so I will just be friendly.”
On the other hand, there are actually situations where a spark of life is noticeable, and then one can try to tell them that they should change something, that they aren’t too old to try something new! But one really shouldn’t be angry, because parents are difficult out of stupidity, not malice. They wish their children only the best, but they can hardly understand their own situation. And if you are dependent on their support, then it is very difficult for them indeed when you argue with them too much.