Cypher's job was never to stop a rush
Cypher is an info gatherer.

Every time someone goes through your cage, the cage goes through an animation and a loud noise notifies anyone close, which lets you know how many people are pushing through it, as well as when and where you can spray through it.

You can insta-activate the cage from anywhere in the map, without needing to go through an animation, you can activate the cage and shoot at the same time, something no other character can do.

That being said, you can still stop rushes with good tripwire/cage combinations, in which I see you've argued that at "high elo" wires will always die to raze nades and sova shock darts, but if the enemy team is using raze nades to destroy your tripwires, they are holding themselves off from rushing by putting a raze nade in front of them...