It is mentioned in a Hadith:

إن الله كره لكم ثلاثا: قيل وقال، وإضاعة المال، وكثرة السؤال

“Indeed, Allah dislikes for you three things: gossiping, wasting wealth, and excessive questioning.”
(Sahih Bukhariy, Hadith: 5975, 6473, 1477 and Sahih Muslim, Hadith: 4458-4461)

Wasting wealth can manifest in two ways: spending on haram (forbidden) activities and overspending in an extravagant manner. This wastefulness has driven us into a cycle of competition and boasting with one another. Such rivalry, as highlighted in another Hadith, can lead to our destruction.
Listen here to my talk encouraging abstinence from all sin on the auspicious odd nights of Ramadan in which I have also discussed the sin of extravagance.