Answer:
Three little letters, a paradox to some. The worse that it is, the better it becomes.
The French word for 'fun size' in women's clothing.
What measures out time. Until in time all is smashed to it?
What has three ways out and just one way in?
Break it and it is better, immediately set and harder to break again.
I am the fountain from which no one can drink. For many I am considered a necessary link. Like gold to all I am sought for, but my continued death brings wealth for all to want more.