I understand that Jesus died for all people, but not all people receive the benefit of this.
You can love all people and therefore invite everyone to your birthday party; but not all may come, possibly because they do not value you and your invitation.
Conceit could be the problem: ones might feel you aren't good enough for them. And there are the ones who consider themselves to be too good and too smart for Jesus.
But Jesus died indeed for the whole world.
And we see how Jesus on the cross prayed >
"Father, forgive them, for they do not know what they do." (in Luke 23:34)
So, Jesus in His heart desired and prayed forgiveness to people who still were busy with hating and torturing and murdering Jesus who is God's own Son. But ones of them possibly did not trust in Jesus and join Him and share with Him and follow Him.
But, by the way, Jesus is our example of how He wants us to love any and all people and have forgiveness ready with tender and adoptive caring ready for any person.
Yes, Jesus died for all sins, including unbelief and the conceit thereof, in a number of cases. Plus, this is our example of how we need to stay ready for love with any impossible and conceited person.