Caffeine withdrawal is no joke. I think most people just drink coffee so regularly they never experience it.
I spent years drinking 2 to 4 cups daily and also smoking cigars. I didn’t notice much from caffeine, as I’d gotten into it in high school to wake up for cross country practice. We were running by 6am.
A couple years ago I had a panic attack, and couldn’t tolerate any stimulants until I healed using deep health techniques, but that first week after cutting coffee, I felt fatigued and beat up.