It really is. Sometimes it's useful like 3d-printing (make custom thing), but often it's just like having the right replacement part for something that broke.
Here's some real examples from myself:
Repairs (crotch of my jeans x 10, broken strap on backpack)
Functional modifications (add pocket to jacket, add attachment points to a bag so I can mount it on my bike rack, lined a jacket with some scrap wool material to make it warmer)
Aesthetic modifications - what got me into it in the first place (slim shirts, taper pants, hem pants, replace buttons)
Small custom makes - mostly leather (my wallet, passport holder, kindle slip cover, tote bag)
Large (involved) custom makes - bicycle frame bag, hammock underquilt
Repairs (crotch of my jeans x 10, broken strap on backpack)
Functional modifications (add pocket to jacket, add attachment points to a bag so I can mount it on my bike rack, lined a jacket with some scrap wool material to make it warmer)
Aesthetic modifications - what got me into it in the first place (slim shirts, taper pants, hem pants, replace buttons)
Small custom makes - mostly leather (my wallet, passport holder, kindle slip cover, tote bag)
Large (involved) custom makes - bicycle frame bag, hammock underquilt