Steel rewards consistency: an impact is seen and heard at once, so you can keep going without walking down to check. It is excellent for working on sight acquisition, positional consistency and follow-through, as long as you do not turn the session into a speed contest.
The risk is putting rate of fire ahead of accuracy, because the feedback feels good. A session entirely on steel with no paper check can bed in bad habits that nobody sees.
A steel target is chosen for a given caliber and distance, set by the manufacturer and the range rules. Shooting closer than intended, at a cracked target or with a caliber it was not made for increases the risk of ricochet and splash back towards the shooter.
Check the target's condition before every session: deep impacts, deformation, cracks, loose fixings. A target that has taken a lot of hits gets replaced. And as always, eye and ear protection stay mandatory for the whole session.