It is customary for me to enjoy an espresso (occasionally two) with a bar of dark chocolate after dinner. I sleep well not much later. 100s of thousands, if not millions, do this as a matter of culture.
What if you think you sleep well now, but it turns out you can sleep so much better?
I'm not saying you will (I'm neither pro- nor anti-caffeine). But I am saying that unless you've tried it, you have no way of knowing. And I know lots of people who have improved their sleep in various ways, who thought they were sleeping normally/fine, and then discovered they actually hadn't been -- they just didn't know any better.
(And even if millions of people do something as a matter of culture, that doesn't mean it's good for your health. There are tons of cultural practices that are bad for health, or bad for a subset of the population.)
I cut all coffeine I was aware of. Coffe, Pepsi Max, everything.
I felt no difference and noticed no change in my health tracking. The only thing I noticed was it was less social.
That said, there have been times were I had to cut down on coffee, but not because of sleep.
I personally have to make sure that if I consume caffeine in the morning, it's enough to overcome this paradoxical effect, otherwise I often end up falling back asleep.
But this goes deeper into philosophical discussions about human life and things like art that transcend the banal “useful/useless” prism.
Few things have disappointed me as much as caffeine research. If we can't get something so direct properly studied, what hope does 90% of science have?