It may be a leap to try bicycle bib shorts for the first time but they offer many advantages over shorts - which is why all professional and vast majority of better riders use them by preference!
Who does not use bib shorts?
Many triathletes especially in competition where they use a short to pull over their swimming gear, or use a tri short or tri-suit with an integral thin chamois.
More women use knicks than men - for the added convenience in bathroom breaks.
Casual riders who use "Mountain Bike Shorts/Shy Shorts" for reasons of modesty and the added convenience of pockets. Though true mountain bike competition riders use bib shorts.
Hope this helps watch the video for more.