Boromir's downfall was caused by 🧝Galadriel

[Ent]

Well, whether it is a true 'catalyst' or not may be questionable. But most certainly, she was one of many contributing factors.

What it can also be said Galadriel did, was offer him a chance for CHANGE - away from his innermost desire. To CHOOSE to let it go, rather than let it continue to inflame.

We always look for 'reasons and faults.' But playing off @Deimos' comments, we and we alone are the ONLY one's responsible for our choices. Everything else is just a factor - a factor on which, in itself, we also need to make a choice.

The end result is usually a series of compounding choices, either for good, or for ill.

Boromir's final fateful action in trying to take the ring is nothing other than failing to resist the multiple opportunities he had to correct his thinking, and make alternative choices. Let's not blame his station, his job, his background, Galadriel, or anything else. He simply failed... just as Isildur did in not pitching the ring into the fire to begin with.

His "final act" (confessing to Aragorn) was yet another choice. (I do believe a confession to a human fits within the confines of Tolkien's "religious element" of "repentance" set into his Mythology. Tolkien posits a religion of "works" throughout.)

And Boromir's just prior act was also a 'choice' - the defense of the other hobbits, his final act demonstrating support for the quest.
One who had utterly fallen to the temptation would have chosen otherwise, in salvation of self, we can certainly conclude.

 

[Sword&Sorcery]

I disagree.
She did not reveal to him that which he did not know, rather she revealed what he knew to be true.

With or without her influence he was destined to act as he did because it was what he truly wanted and was fated to act upon.

She was not a “catalyst” and did not have any effect on what was to happen afterwards.

This is exactly where Galadriel acts as a catalyst. Reread Olorgando's post about "catalyst".