Sorry along with the ability to believe is the ability to not believeExactly it's hid from them. If its hid they cannot believe. So much for your universal ability to believe.
but you did not address the difficulty of your position
Context
2 Corinthians 4:1–4 (KJV 1900) — 1 Therefore seeing we have this ministry, as we have received mercy, we faint not; 2 But have renounced the hidden things of dishonesty, not walking in craftiness, nor handling the word of God deceitfully; but by manifestation of the truth commending ourselves to every man’s conscience in the sight of God. 3 But if our gospel be hid, it is hid to them that are lost: 4 In whom the god of this world hath blinded the minds of them which believe not, lest the light of the glorious gospel of Christ, who is the image of God, should shine unto them.
The lost here are those who heard the gospel did not believe and were blinded by Satan
not all the unsaved
Verse 4. In whom the god of this world, &c.] We see here that those whose minds are blinded, are they who believe not; and because they believe not, their minds continue in darkness, and are proper subjects for Satan to work on; and he deepens the darkness, and increases the hardness.
Adam Clarke, The Holy Bible with a Commentary and Critical Notes (vol. 6, New Edition.; Bellingham, WA: Faithlife Corporation, 2014), 328.
but the verse involves Calvinism in some difficulties
If man is born totally unable to believe the gospel why would Satan need to blind anyone also if grace is irresistible how could Satan blind anyone
If Christ did not die for the nonelect, of what are they blinded? It cannot be that they are blinded of Christ’s death for them and their need for faith if Christ never died for them. They cannot be blinded in their unbelief because they have nothing to believe or to disbelieve since they have no relationship to Christ’s death!