Quoting it helps to make it easier when it needs to be referenced, but with the forum scrapers we have now that log all posts made, the original posts with the address can always be pulled up if the need arises.
For older posts that were made before forum members started keeping logs, quoting is the only way to preserve them.
If a post with address is quoted in the forum, it is better than rely on any website, any scraper because they can stop working anytime.
When they are working, we can use them but if they are dead, only posts in the forum can be used as reference. Scrapers can help but not always and a post with an address is helpful if it is not deleted. A quote for that post can be deleted too but it must be very coincidence to see both the original post, the quoted post are deleted.