Some of these comments are a classic case of "since I have them they must be the best."
Two decades or more ago I purchased some cycling specific suspenders. They are thin, elastic, adjustable in tension and in world championship colors. I have used them on countless number of shorts, with the waistband loose, for all those years. Since shorts cost much less than bibs, the savings has been substantial, without a sacrifice in comfort.
Having said that, I also own bib shorts. And they are comfortable, but no more so than the shorts & suspenders. And far less flexible. Unhooking the suspenders and pulling down your shorts to pee is way easier than the machinations needed using bibs.
I wish I could find a backup pair of cycling-specific suspenders. Any leads on that?
Steve