I have a tiny handful of friends in IT older than I whose careers are still thriving in the UK. Most are specialists of some kind. I wish them well.
For the first >50% of my career, my speciality was that I wasn't a specialist. I can work anything with a keyboard and a display, fix it, tune it, make it talk to anything else, or at a push virtualise it.
But that's an obsolete skill in the near-monoculture of today, when IT means Unix, Windows and nothing else, talking Internet protocols. It's all boring now.
Usefully, though, I also write, so I changed course and became a tech writer. That's working out OK so far.