It is career advice. Whether it is pretty good is debatable. To suggest that you look at people slightly ahead of you and use that as some kind of magic mirror

It is career advice. Whether it is pretty good is debatable. To suggest that you look at people slightly ahead of you and use that as some kind of magic mirror is just so tragically flawed. First, it supposes that the you of now, inexperienced as you are, can properly evaluate not only what is going on in these older coworkers lives, but that you will also properly appreciate how your own tastes will change between now and then. Secondly, you are looking at pure survivorship bias. You aren't going to see the folks that did a 5 year turn doing development and then found some other direction to take their career in. If you are a new hire and look at the 50 year old dev on the team and assume your career might go the same you are taking a very narrow vision of the future.