>>11859274"Work on things in the background" does not mean "have a job in the field," it just means "keep in touch with the relevant research in your field" and "don't let your skills rust out and become irrelevant."
Think of it like how people look at history reps. You want to keep going back and re-learning historical information, because our understanding keeps changing as we gain more information. If you were to try and assess the Roman culture based solely off of Edward Gibbon today, you'd be considered nearly irrelevant, because you haven't kept your knowledge base up, even if it is a foundational piece of work.