Maybe others do understand.
And some have answered you.
I think it was
@cv5 who mentioned how Paul in Romans5 uses "all" interchangeably with "many". IMO that should make us think because Scripture does not always present for our convenience, cultural norms, linguistic styles... And Paul for instance can be referencing Isaiah and clarifying that "many" should be understood as "all".
There are ways these wordings have been answered by interpreters for generations. Yet each side of the debate won't accept the answers of the other.
Translations are ESV:
Many:
Matthew 20:28"Even as the Son of Man came not to be served but to serve, and to give his life as a ransom for
many."
Mark 10:45"For even the Son of Man came not to be served but to serve, and to give his life as a ransom for
many."
Isaiah 53:11–12"By his knowledge shall the righteous one, my servant, make
many to be accounted righteous, and he shall bear their iniquities... yet he bore the sin of
many, and makes intercession for the transgressors."
Hebrews 9:28"So Christ, having been offered once to bear the sins of
many, will appear a second time, not to deal with sin but to save those who are eagerly waiting for him."
All:
1 Timothy 2:6"...who gave himself as a ransom for
all, which is the testimony given at the proper time."
1 Timothy 4:10"For to this end we toil and strive, because we have our hope set on the living God, who is the Savior of
all people, especially of those who believe."
2 Corinthians 5:14–15"For the love of Christ controls us, because we have concluded this: that one has died for
all, therefore all have died; and he died for
all, that those who live might no longer live for themselves but for him who for their sake died and was raised."
Romans 5:18"Therefore, as one trespass led to condemnation for all men, so one act of righteousness leads to justification and life for
all men."
Titus 2:11"For the grace of God has appeared, bringing salvation for
all people..."
John 1:29"Behold, the Lamb of God, who takes away the sin of the
world!"
John 3:16"For God so loved the
world, that he gave his only Son, that whoever believes in him should not perish but have eternal life."