It's not just for their resumes, it's for the pleasure and challenge of learning something new, the feeling of confidence and with-it-ness when you get to say "

It's not just for their resumes, it's for the pleasure and challenge of learning something new, the feeling of confidence and with-it-ness when you get to say "yeah, we use that, I set it up" when people are talking about the latest and greatest thing, the fear of missing something transformative and getting left behind. It all boils down to nurturing a person's confidence that they are good at what they do and their ability to sound that way to other people, so "resume" for short. And even if it is just for the resume, it's smart and understandable. Consider the difference between, "Eh, I evaluated some NoSQL options here and there, but it seemed safer to stick with Postgresql since we didn't have a compelling reason to experiment. Postgresql works fine at the scale of our product and we're very familiar with it," versus, "Yeah, we used Mongo for a project and it was a shit show, switched to DynamoDB which has been solid. The product is still 80% on Postgresql, but we use Cassandra for analytics, and of course we run InfluxDB for Grafana, which we're going to replace with Prometheus for better scalability." These could be two people facing exactly the same serious of engineering choices, with the first guy making the better decision every single time, but the second guy sounds like the kind of curious and hardworking person you'd want to hire, while the first guy sounds maybe... stuck? Counting the days to retirement? Maybe boring SQL guy has saved his company a ton of engineering work that they were then able to invest in product work instead of engineering, but when he and NoSQL dilettante guy are both interviewing at a new company that wants people who are "curious" and "passionate" about "dedicated to learning and growing their skills" and "ready to meet new challenges head-on" he has to be worried about sounding like a dud. But I've never met anyone in the last 20+ years with thousands of engineers who was doing it for their resume. It's not something you can distinguish from being eager to learn and overenthusiastic about new tech, which we all are to some extent.