Being wasteful is a bad thing. Having excess for oneself is a bad thing. Allah SWT addresses these facts in the Qur'an as a reminder for us all to live more fruitful lives.
"It is He Who has brought into being gardens, the cultivated and the wild, and date-palms, and fields with produce of all kinds, and olives and pomegranates, similar (in kind) and variegated. Eat of their fruit in season, but give (the poor) their due on harvest day. And do not waste, for God does not love the wasteful." [Quran 6:141]
When we have so much, it is our turn to give to others. Use what is of use to us, and give away that which is unnecessary for our purposes. Wasting our resources does nothing to serve society.
"Children of Adam! Wear your beautiful apparel at every time and place of prayer and eat and drink. But do not be excessive – verily God does not love the wasteful." [Quran 7:31]
It is important to be modest in how we present ourselves and in using what we are given. Showing off is a form of waste - appreciate what you are given to wear everywhere you go, but do not wear inappropriate clothing at the wrong time - like a flashy suit to a Janazah. Utilize what you are given, but do not be excessive about it.