Tech I think is particularly bad for people feeling insecure. We act like it's normal and shame those who don't do this, but the idea of having to constantly revamp your skillset every ~5-10 years to remain employable is not normal. My dad has been a lorry (truck) driver for 40 years, and aside from a few changes in vehicle tech nothing has really changed much for him.
I know some people who had great tech jobs in the 90s, but those skills are now obsolete. I see people even today who I'm convinced won't be employable in a few years. For example, there was a guy at the last place I worked who just wrote HTML and basic JQuery code for one of our legacy products. He had been doing this for 10+ years, and recently it was announced that they would soon be pulling the plug on that product. I don't know what that guy is going to do – realistically no one is hiring for HTML and basic javascript today.
My opinion is that non of us in tech should feel secure. I've seen some really brutal layoffs over the course of my career where even the most value people are chopped because an order has come from above. You could be the most valuable person on your team by far, but if the company no longer deems your project needed or your skillset can be outsourced for much cheaper then non of it really matters.
I feel sorry for people who aren't geeks in this industry to be honest. I find I can upskill quite easily just because I enjoy tech so want to learn new things. But I understand that most people probably don't want to finish work to continue working on personal projects that require learning new skills.
My advice to everyone in this industry is to just enjoy it while it lasts and to build up savings. That's really the only way you can reduce stress and feel any sense of security.