Flexible? In these days where unemployment rules, companies will reject your application if you have not 5 years of experience with the exact complete toolchain they use. Doesn't matter if you have been working 15 years in the same industry and 10 years on the same kind of job, and that you could adapt easily and quickly to other toolchains, jobs or industries, they don't care, they can find someone that doesn't even need to adapt. So the more years pass, the more you get stuck in the exact same thing, despite your theoretical flexibility.