Evolution

I can never fathom the use of nails. I would have spent at least 0.0005 percent of my life cutting my nails. And the hand ones are useful, at least for a selected use cases, but what are the nails on the feet doing ?! Why do we need them ?
If the evolution theory says that humans lost their tail as a part of the evolution process cause they didnt use it much, then why are the nails still growing and growing and growing ?
Man! we lost to the damn fish too! It was successful in growing fins after being extinct for some years, but we ..no! we couldnt even shed of the nails. Nails are fine, no problem with them - but why the heck do they grow !?
After the 20th century, evolution has made us grow a waist to adapt to the low-waist jeans we wear compared to the ones of 70s where people used to dress their pants on their chests. I bet the shirt length was trivially small in that period of human history. The threshold was 3, you were allowed to display only 3 top buttons of your shirt above the trouser. Such high was the trouser dressed!
With the low-waist jeans picking up these days- according to the evolution theory we may end up having a waist at a place where our knees are today like a Dachshund! (provided we evolve :)