Now you can use them more than 5 years ago,
btc were said created on 2008 . You compare btc when it was 5years ago or on 2015 , that was 7 years later from 2008 and that's long enough for btc to be known and btc was actually starting to get popular that time but another 5years have passed and we are now on this current date 2020 and the markets for btc got even much better/wider .
and 1 2020 btc = x30 2015 btc, so who cares if it's more expensive now?
You mean the price of 1btc now times 30 than its price on the year 2015 . According to my research it shows that price of btc on year 2015 was $395–$504 ( that was early November ) . Your calculations could be right . The price will play at that range . No complains on the price of btc now but people love it , those that complain wanted more or complain because of the high fee