It causes:

- High heart rate and blood pressure

- Increased risk of arrhtymia

- Less deep sleep

- Disruption to your cortisol level dynamics

Whether you consider all of them not "bad" or worth the benefits is up to you. People also consider moderate consumption of alcohol worth its benefits.

Everyone has a different risk profile. Know the risks and choose as you please.

Your sure those effects have manifested in studies for moderate caffeine consumption?

Maybe the general consumption went up over the years. I think around 200mg per day was considered safe? That would be around two European-sized drinks.