Ask HN: What new project or tech is worth learning in 2022?

Hi HN, I have a long list of things to learn but I always try to keep one or two languages, API's or even things to tinker with (hackrf, arduino, rpi...) on my radar. But there is so much stuff out there I can't tell what is a fad and what has actual value. What has been a rewarding experience that also has value that you would recommend as a leanrning goal? For context: this is for personal development not a career/professional pursuit.