What stops commercial ice lollies from being rockhard? In the UK you can purchase ice lollies/suckers that are pretty soft to eat.
However, if you were to make your own in an ice lolly mold they'll be rock hard like ice normally is.

What do commercial companies do to their ice Lollies to make them soft to eat.

I'm unsure if this applies to other countries such as the US, I'd assume it does.
If they are rock-hard, they need more sugar (or you're one of those people that use artificial sweeteners and they don't have the same effect that sugar does.)

About 30% sugar is a typical proportion that works - feel free to experiment. i.e. mix 300g sugar with enough water and flavoring to make 1 liter of mixed solution. If using juices, calculate how much sugar they contribute from the label information and add enough more sugar to reach 30%

Pectin can also be helpful. You need things that interfere with the size of ice crystals. Jam is one way to get it, (and some sugar - again, read the label to find out how much) or you can get the pectin made for canning your own jams.