My experience is that age isn't necessarily a breaking factor in all but the most frivolous tech companies, but those are the ones you shouldn't care about anyways. The key skill/ability is mostly having the capacity and willingness to understand and accept new paradigms and techniques instead of being enamored to and clinging to "that's how its done" philosophy. Of course, I'm not suggesting dropping good practices just because they are old; simply having the willingness to do an objective analysis and comparison and make a rational decision... that is really important. And almost every older engineer I've worked with have shown precisely these qualities (maybe a survivorship bias?)

i don't know how to get that data, but i'd love to see it