Steel chastity cages outsell silicone, we'll say that from the outset. Perhaps it's the link between your cock being in prison and the steel bars of a steel chastity cage that hold a stronger symbolic meaning than a silicone or plastic one could.
It could be the weight that they carry. As steel cages get longer, they of course become heavier so the more gravity will have an effect on them and the most the wearer will subsequently be aware of wearing the cage. Perhaps it is that the wearer want's to be reminded or perhaps the key holder want's them to be reminded!
The robust nature of steel cages make them safe options for the day to day grind. Something that you know isn't going to snap or damage no matter what is going on. Many of these cages have integrated locks built in allowing for an extremely secure whilst compact setup, making steel cages pretty much bullet proof.
Of course with the rigidity of steel comes the shape in which your cock will be entombed. Whatever shape the cage is, that's the form that you'll take from thereon-in. Whether it is a straight cage, a downwards bend or a short abrupt stop, it will mould you without compromise.
Whatever the reason, the appeal, we hope you enjoy your chastity journey and continue being curious in exploring this fascinating element to relationships and play.