I quit coffee in January 2018. I did it slowly, weening down to a half cup per day, then switched to tea, and weened it down to herbal teas and zero caffeine. Took about 3 weeks, but I never had withdrawal symptoms. Before quitting, I drank at least a cup a day, everyday, for richer or poorer, in sickness and in health, for about 2 decades. Literally, zero missed days.
My motivation for quitting was to improve general health, especially sleeping. It was easy for me to fall into long cycles of coffee in the morning, beer or wine in the evening. I figured I would be better off letting my body have a natural circadian rhythm, not daily uppers and downers. It was part of a broader effort to live better—worth mentioning that I’d just turned 40 in 2017, so it was kinda like a midlife crisis (but really more of a midlife course correction, which cycling and TR are now part of, too).
What did I achieve? My sleep improved qualitatively—but I still wake at 3am many nights (ahem, like right now). I’ve drastically reduced alcohol consumption. One benefit that I under appreciated beforehand was the reduced cognitive load of thinking about needing coffee every morning to keep withdrawal symptoms at bay. It’s nice (especially on weekends, when traveling, etc.) not to worry or even think about when and how I’m going to feed the addiction beast. Yes, it’s a very small thing, but I have a million things to think about and remember on a daily basis—I’ll take one less anyway possible.
I stayed at zero caffeine for most of 2017, but have added it back in selectively, prompted by other caffeine discussions here. I’ve found it helps reduce my RPE, so I have a strong cup from my moka pot before tough sessions. Usually that means Saturdays, which is perfect.
I love coffee, but I would not go back to the daily dose days. I agree with others that your stated motivation for quitting seems suspect/weak/insufficient. But I encourage you to go for it anyway. Only when you’re “clean” will you be able to do some self-testing to see whether coffee improves performance. And you might discover unexpected benefits. Plus, it’s so easy and tasty to go back to old habits. So, go for it and tell us all what you discover!