Inflexibility is in my experience more often associated with a person than with their age. I've seen 30 year old devs that were absolutely incapable of changing over to new tech as it became available and I've seen 55+ people dig in with gusto. It's a mentality thing. Sure, mentality can change over time, maybe someone that's older is going to give something new a little while longer before hopping on the bandwagon or maybe they've already seen something similar fail in the past which is why they might be reluctant.
But flexibility is a hard-to-measure parameter to begin with and you need to know the people and their reasons before you can make call about it rather than simply their age.
But flexibility is a hard-to-measure parameter to begin with and you need to know the people and their reasons before you can make call about it rather than simply their age.