As a kid I felt so frustrated with how bored I got that I had tantrums, on one or two occasions.

But nowadays I don't get bored at all - phone, video games and work/study mean there's always something to do, and not enough time in the day.

Boredom can be useful. Use it for self reflection, exercise, et cetera. I would credit how bored I was as a kid with how smart i was as a kid.