When Christ was numbered with the transgressors (see below verses), those He represented could no longer be numbered as transgressors since He took their place - the concept of double jeopardy would not permit Christ and those for whom He stood in, to both be so numbered - given that Christ became numbered. If Christ's sacrifice truly applied to everyone as you say, then He alone would have been numbered as the only transgressor (yet He wasn’t), with no other transgressors remaining. However, as the verses below clearly indicate, Christ was numbered
with transgressors, but not that the transgressors were numbered with Christ - meaning those He was numbered with still remained transgressors, they, apart from Christ. Therefore, given as they remained transgressors even when Christ was a transgressor, means that it is not possible for those transgressors to ever be covered by His sacrifice.
[Isa 53:11-12 KJV]
11 He shall see of the travail of his soul, [and] shall be satisfied: by his knowledge shall
my righteous servant justify many; for he shall bear their iniquities.
12 Therefore will I divide him [a portion] with the great, and he shall divide the spoil with the strong; because he hath poured out his soul unto death: and
he was numbered with the transgressors; and he bare the sin of many, and made intercession for the transgressors.
[
Mar 15:28 KJV] 28 And the
scripture was fulfilled, which saith, And he was numbered with the transgressors.