Maybe medically fine, but that doesn’t mean it is ideal. And how fine it is varies (drastically, I think) from person to person. I know caffeine is horrible for me, even 150 mg/day - it disrupts my sleep, clouds my thinking, and makes me more irritable (not helpful as a trial attorney). I started drinking it late in life (32 then, 38 now) and every time I quit I feel infinitely healthier. I am 5 days in to (hopefully) quitting caffeine forever. For me, it is a drug worse than alcohol. I have a feeling a lot of people are in this boat and just don’t realize it because they have been consuming caffeine beverages for so long.
I did it because when I was on an elimination diet, it was recommended to quit caffeine too. Hasn't seemed to have much effect. I sleep the same, still grind my teeth, still have psoriasis. I've cut everything from diet except salt, vegetables, fruit and fish.
I don't need to lose weight though. Diet more for just other health reasons. 5' 11" 165lb. I could probably lose a little belly fat, but nothing crazy right now.
Cups or mugs? Most of us, when we pour a mug of coffee, pour about 12 ounces, which is a cup (8 oz) and a half. So if you have two mugs of coffee, you're actually drinking about 3 cups.