Not just any collagen. Collagen I is what subtype provides suppleness to arteries.

"Collagen type-I degradation is related to arterial stiffness in hypertensive and normotensive subjects"

 

There is this huge body of work that contradicts itself if you don't read the above Nature article.  Yes, Linus Pauling was right, but greedy usurpers did not help but to obfuscate everything for the worse.  It's almost as if they are paid agents of disinformation or saboteurs.  As publicly noted by The Los Angeles Times global mainstream associated press and media, Matthias Rath himself would go on to sue Linus Pauling for the same things he initially claimed to Linus Pauling were unimportant to him ($$$money$$$ aka IPR aka patents) in order to gain a foothold at the Palo Alto laboratory.

It's not just any collagen, but Collagen I which is important to the peculiar supple, yielding, resilient, rebounding, hydraulic strain resistant type of strength of arteries.  Modern material science could not come up with this blended material because arteries are self repairing and no non-living hydraulic tube could last very long under the same kind of stresses.  Arteries need ample vitamin C to repair and make more Collagen I.  The wrong overabundance of other subtypes, say ColIII or IV or V cause pathological stiffness and/or fibrosis, which contributes to a more brittle artery structure that instead of giving way and stretching and recoiling, stays motionless and snaps apart beyond a certain systolic blood pressure.