Been coding professionally since the mid-80's. I still sit in front of 3 computers (win10, mac, linux) every day writing code for various projects. Mostly embedded on NXP/Renesas for ODMs (lots of security and ML these days), but also device drivers on Linux/Windows, native windows tools, and as a bonus SPA dashboards for IoT/cloud (Vue/Node). I use python+excel extensively for behind the scenes analysis.
To stay current, I read multiple newsletters because HN tends to skew to the web and misses large parts of the industry. It is rather myopic that way.
People talk about tech leaving grayhairs in the dust, but that discussion always seems to be related to web front-end, which is like a fraction of the industry. Sure there will always be a need for a fast flashy website that scales to billions of users, but optimizing C in embedded space, or debugging a Windows bulk USB endpoint, or customizing UDP for multicast, etc. will always be necessary, too.
Realize as you older that you are going to be charging a premium for experience, so you have to build breadth while you are young to compete when you are old. If you just stick with one tech your whole life you won't be able to leave it.
And you can only get that kind of breadth from decades of experience.
There's literally no short-cut to age.