Mostly no, partly yes. Shoes will crease no matter what, that's just what happens to animal skin wrapped around weird human feet that flex in a dynamic way. But you can mitigate creasing by 1) buying shoes that fit and 2) using shoe trees when appropriate.

The best way to size for shoes in the US is to get reliably measured on Brannock device and know how a given shoe compared (TTS, long, narrow, wide, short). For example, I measure 8D (borderline E) on Brannock and I wear: US 8D on Allen Edmonds' 511 last, US 7.5E on Allen Edmonds' 65 last US 8 in Adidas Stan Smith, US 7.5 on Converse Chuck 70s, US 8D in LL Bean Katahdin, US 7.5D on Redwing's 8 last (Iron Ranger).

Cedar shoe trees (also known as 'stretchers') are primarily used for their antimicrobial properties to fight funk and sweat-wicking properties to remove moisture from the leather, thereby extending the life of the shoe. A secondary function is shape retention, as the wooden tree provides structure needed to straighten out the shoe and mitigate creases. Someone over at r/goodyearwelt did a month-long experiment on his boots, using a shoe tree overnight for one boot but nothing for the other, and there was a marked difference of shape/creasing between the two.