It's neither good nor bad in absolute terms. It can be misused, abused, and overdone like any substance.

In my experience, the people who benefit from quitting caffeine were either using far too much of it, were drinking it too late in the day (interferes with sleep), or were using it to cover up other problems like poor sleep habits.

The person drinking a cup or two of green tea in the mornings after going to bed on time is going to have a different relationship than the person drinking very strong coffee drinks all day long to stay awake because they've been scrolling on their phone until 2AM every night instead of trying to sleep on time.