You can't go hiking when you are 75. You'll probably be sitting on a chair. You can't also go drinking and dancing in some cities around the world and coming back to your hotel room with a date. That can't happen at 75 unless you are paying for it. I also don't think you'll enjoy it as if you were 22.
The truth is: You should save/spend and optimize for your perceived livelihood. Unless you have an agenda of passing your wealth to your children. I'd rather cease my existence at 75 or 80 than struggle with illness and pass my wealth to pharmaceuticals and doctors.
But back to the issue. $5 coffee? Yes but only because I can sit at Starbucks for 2/3 hours. They give you electricity, WIFI and some starbucks do have rather, very nice, views. Buying a take-away starbucks everyday because you are too lazy to make coffee is stupid, however. (or rich enough)