There are plenty of attempts to find atonement theories that avoid the barbarisms of some penal substitution (PSA) proponents, but avoiding PSA altogether is unavoidable. Here’s what it claims:
1. Humans sin.
2. Sin has serious, ultimate consequences before God.
3. The consequence of sin, its punishment, is death.
4. Jesus died to bear (and bear away) the consequences of sin (and sin).
5. Christians proclaim the forgiveness of sins through the death of Jesus.
There is only one way to avoid the necessity of penal substitution, and it involves these claims:
1. Believe that sin has no final consequences.
2. Eliminate the sin-bearing intentions/consequences of Jesus’ death.
3. Claim that Jesus’ death did not deal with the consequences/punishment of sin.
Hence, to claim he forgives sin by death means he has taken our place in his death and in that death absorbed the consequences/punishment of sin.
That is called penal substitution.
The problem I see many addressing is not penal substitution but propitiation, namely, the belief that on the cross Jesus bore the wrath of God against sin. In other words, penal substitution includes propitiation (for many) but it cannot be limited to propitiation. To reduce penal substitution to propitiation is a mistake.