I had always thought they were for extra bling and accents. Didn't know they were so you wouldn't stub your toe or fall off until I found TFP and and read that in some posts. I don't think they are dated and our PB puts them in all their pools. We love them!
Theres so many ways to do them. For ours, they cut the 6" waterline tile in 3x3 squares and put them in a diamond orientation on the steps. We didn't care for that look. We have seen some great ones done out of the glass and all kinds of other ideas. For us, it just seemed like it would date the pool or be out of style quickly. Hopefully I keep the water clear enough people can see the steps!
brett