If you want job security – run a funeral home, become a forensic pathologist. Especially the latter. Somehow people won’t stop dying. Sure, those do not scale up but it is job security you are after, right?
In IT the concept of job security does not exist. It doesn’t. Doesn’t matter how good you are, how much you know, how great is your “brand” or anything, there’s no such thing. It is best to accept that you are in a constant trial period. Tomorrow could be your last day and that’s okay. There are 100s of things that can happen, not under your control, and each can lead to you getting fired, managed out, laid-off or the whole business sinking (with everyone onboard).
Do you know what does not sink? The business with the ones who are no more. You won’t get rich, but you won’t be living in a box either.