Hi, I switched to thongs three months ago because I wanted to get rid of VPLs under my work pants, and I have found that my buttne disappeared! It makes sense because regular panties tend to sandwich sweat, oil, and dead skin cells between the fabric and cheeks; with breathing room around the buttcheeks and well-fitting, flat, breathable coverage right where it counts, less moisture from sweat accumulates, so fewer acne-causing bacteria can build up!
I used to have buttne when I wore regular panties and even when I went commando; but with minimal fabric that wicks away moisture, my round, soft buttcheeks are as smooth as canvas! Thongs are the oldest human garment in history and prehistory; due to this fact, there must be a good reason, and that's the sheer practicality of no extra fabric bunching between the cheeks and causing uncomfortable wedgies!
Oh, and thongs do NOT cause or increase risk of UTIs; in logic, it makes sense; but as long as it is well-fitting, it will NOT floss germs between the front and back parts; it will stay well in place and serve as a practical, moisture-wicking garment which was originally designed to protect genitalia from the elements and such on all genders! By its wicking properties, thongs may actually decrease the risk of UTIs, if they improve buttne, contrary to what many say!