The reality though is it may be the employer who has caused the employee to fall behind/out of relevance. Quick example: while working on a federal contract I

The reality though is it may be the employer who has caused the employee to fall behind/out of relevance. Quick example: while working on a federal contract I had a co-worker who was in charge of the contract's Altiris infrastructure. That was all he was allowed to charge time for on that contract and it was the only contract he was on. To learn something new he either 1) had to carve it out of his personal time, 2) commit federal timesheet fraud or 3) take a pay cut. Meanwhile others of us were being sent off to learn new products like vSphere. Speculation was that our management was deliberately monopolizing his time on this one thing because it was getting hard to find people to do Altiris and they didn't want to pay for teaching him something more relevant and have him use it to get a new job elsewhere. Eventually, he did find another job and moved on, and I got a steady stream of recruiters who saw Altiris on my resume because it had been a big part of my duties at that and my previous employer. Nope, I already know where that trapdoor goes, thanks but no thanks. Now if your employer does offer continuing-ed/tech-training and you don't take full advantage of it, that's on you, although even that can be hard since some employers offer it only if it's job-relevant -- e.g. only the Windows tech staff can take Microsoft training, only the Linux staff can take Red Hat courses, only the networking staff can take Cisco courses, etc.