I guess the reason I don’t fit into most non-Japanese fast fashion is the same reason people complain they can’t fit into Muji / Uniqlo clothes. Everything else looks funny on me unless I get it tailored but off the shelf Muji and Uniqlo is mostly fine (expectations of default body shapes etc)
Not as obvious as when I was scuba diving and every scuba mask that wasn’t made in Japan was way too big for my nose (which is very flat), which was actually a life-threatening issue because using rental scuba masks flooded my mask nonstop, no matter what size or adjustments. Eventually I had to get my own.