We all* limit the atonement. Some its effectiveness and its efficacy (Arminians), others its extent (Calvinists).
A Calvinist says the death of Christ on the cross actually did something in that moment to free all those from sin and death who had been elected by God (insert one zillion verses here). It didn’t simply create the potential for men and women to be saved, but actually saved them in that instant. In their time, God granted them gift of faith. In this view, God gives a totally dead person mouth to mouth and resuscitates us from a state of death.
An Arminian would say that Christ died for all (insert hundred verses here), thus not limiting the atonement’s extent but rather its efficacy. It gave us the potential to be saved as we come in by our freewill selection choosing to participate in Christ by faith, but did not as a proper act actually secure our salvation when He said, “It is finished.” He gave a severely injured person a wake up slap about the head to awaken them from near unconsciousness and said, “Medical help is here, do you give us permission to administer it?”
Each limit the atonement in some way.
*“all” meaning those who hold to a view of the atonement that Jesus was our substitute. I am aware there are models which say that Jesus was simply a good moral example on the cross, etc. Not smoking those pipes. That post coming soon enough.