Neither does it invalidate Paul.
But your comment indicates mind reading on your part or some claim to special knowledge or revelation, that you know that Paul *forgot* to mention stuff.
It would be more accurate to comment that Paul *didn't* mention a lot about the Gospels.
My guess is that likely the reason he didn't rehash what happened in the Gospels was that it was because what was recorded in the Gospels for us, was pretty common knowledge to them, back in the days when Paul wrote his letters.
15 And account the longsuffering of our Lord, salvation; as also our most dear brother Paul, according to the wisdom given him, hath written to you:
16 As also in all his epistles, speaking in them of these things; in which are certain things hard to be understood, which the unlearned and unstable wrest, as they do also the other scriptures, to their own destruction. 17 You therefore, brethren, knowing these things before, take heed, lest being led aside by the error of the unwise, you fall from your own steadfastness.
-- 2 Peter 3:15-17
My guess is that likely the reason he didn't rehash what happened in the Gospels was that it was because what was recorded in the Gospels for us, was pretty common knowledge to them, back in the days when Paul wrote his letters.
Oh? How exactly were the Gospels "common knowledge" to these people? In all probability Saint Paul had been martyred before any of the Gospels were even written.
The epistles of Saint Paul can best be described as a theological framework for Christianity. With the exception of First Corinthians chapter 11, they do not contain the words of our Lord.
Go back and read the post I was responding to and then retract or rebloviate as necessary.
Quite so and fortunately a variety of writers provide each provide a part of the whole.