St. Thomas Aquinas in his personal commentary on Matthew says this…
It were better for him, if that man had not been born. From these words an occasion of error follows. For certain men say that to one who does not exist, no punishment is inflicted; thus they say that it is simply better not to have existed, which is contrary to the Apostle’s words (Rom. 9). 17 Hence, according to Jerome, it ought to be said that He is speaking according to the common manner of speech, meaning there is less harm, that is to say, he feels greater torment than if he had not been born. And what is said in Ecclesiasticus 4, 2 seems to allude to this: “I praised the dead rather than the living” (Eccle. 4, 2). And this is opposed to Augustine in his book De Libero Abitrio. What is nothing cannot be chosen. Likewise, what we choose is closer to happiness. But what is not, is not nearer to happiness. Therefore, what is to be said? Can it be that someone choose not to be, rather than to be punished? Therefore, it ought to be said that to be can be taken in two ways: either in itself, or by comparison with something else. In itself, I say that it is not something chooseable, as Augustine says; but in comparison with something else it is chooseable, as Jerome says. Because this is not something in nature, but according to the apprehension in the soul it is taken as something, for example, not to sit. But a choice is taken of that which is apprehended: wherefore, to lack an evil is taken to be something good. When, therefore, one chooses something not in itself but as exclusive of evil, one chooses in this way, as the Philosopher says. By this, the answer to the second objection is evident. He says, therefore, that, that which withdraws more from evil, is taken as something nearer to happiness; hence, to a feverish man to be without the fever seems to be something good, because he seems to be without miseries; hence, it is better not to be than to be subject to miseries.
Fr. William Most says this…
In verse 24 Jesus says that the Son of Man is going, as it was written of Him. Thus He shows full awareness of the prophecies of His passion. Isaiah 53 would be specially in mind, plus Psalm 22 and Zechariah 12:10-11. Jesus adds that it would be better for the traitor never to have been born. Is this a revelation of the damnation of Judas? It could be Semitic exaggeration, so we are not sure, but it seems possible when we consider other instances of great exaggeration, such as Is 13:9-10 on fall of Babylon and Is 34:4 on punishment of Edom and Ezek 32:7-8 on judgment on Egypt.
In verse 25 we have Matthew’s way of reporting the identification of the traitor. Was this the same thing as that in John 13:215-26 and Luke 22:21, or was it a confirmation Judas asked for. More likely the second.
Cornelius a Lapide says this…
For “far better is it not to exist at all, than to exist in evil. The punishment is foretold, that him whom shame had not conquered, the denunciation of punishment might correct,” says S. Jerome. He threatens him with the woe of damnation. For far better is it not to be, than to exist only to be endlessly miserable, as I have shown on Eccles. iv. 2, 3. Wisely does S. Jerome say (Epist. ad Furiam), “It is not their beginning which is inquired about in Christians, but their ending. Paul began badly but ended well. Judas’ beginning was commended, but his end was to be condemned as a traitor.”
Goeth. “By this word,” says Victor of Antioch, “Christ showeth that His death is like rather to a departure or passing away, than to real death. He signifies, likewise, by it that He went voluntarily to death.” Moreover, the betrayal of Judas was an act of infinite sacrilege, perpetrated directly against the very Person of Christ and God. Thus it was true deicide. Wherefore it is exceedingly probable that Judas abides in the deepest pit of Gehenna, near to Lucifer, and is there grievously tormented. And this seems to be indicated by the word woe, which Christ here pronounces upon him above the rest of the reprobates. Blessed Francis Borgia was wont, in meditation, in the depth of his humility, to place himself at the feet of Judas, that is to say, in the lowest pit of hell, exclaiming that there was no other place fit for him, neither in Heaven, nor in earth, nor under the earth, as the due reward of his sins.