In my experience, the younger technician tends towards the quick fix rather than the long term solution - because the latter requires listening to all of the problem. The older man usually comes with a network of colleagues and contacts where not only can he seek (free) advice that can be passed on, but also to whom he can delegate those parts of the solution that he is not up-to-speed on.
I am 67 and still well appreciated by my customers and the firm I work part-time for - even to the extent of getting birthday cards from customers! On a consultancy level I come not as a single person, but a backed-up resource. And I remember to say NO to customers when their solution can be done but not within their budget!