Though it’s not wrong to follow fashion trends, it can be both economically detrimental and contrary against your beliefs. If your religion dictates you to dress modestly, it’s not that you don’t have time to wear shorts but it’s something you only wear on a few circumstances (like indoors and sports). Same with minidresses and miniskirts.
As for the practical side, it’s not just a matter of wastefulness but also that it can be costly constantly following trends when you have other priorities (including making the clothes you want or like to wear). It’s not wrong to want to wear trendy clothing but there’s a reason why basics have staying power. They’re similar and outlast any season due to its myriad practicalities.
It’s not wrong to follow trends but that it’s really not worth your time especially if you not only follow your own principles but also your community’s values, especially if they’re against them. (There’s a reason why nuns dress the way they do.)