The problem with keeping your skills up-to-date is that many of the skills listed in laundry list job reqs are in things that have only existed for a few years. They're things that a sharp college kid can be just as knowledgeable about.

Yes, definitely possible, kudos for pulling it off! But it requires careful long-term proactive decisions and actions. Which is not what most humans are particularly good at. That's why I used the word "scary".

When you are a junior engineer you just crank out code and the level and employability of your skills automagically increase. But after some time this free lunch quietly stops. You suddenly have to manage your career.

Right. People should be less concerned with competing with people in their 20s and more concerned with how they are going to keep up with the other people their age who instead of doing fun, hacker, startup stuff and chasing money spent their time being the "stupidest" person in the room and learning the (an) industry.