I’ve only come across one or two which archive.org didn’t crawl or didn’t have. Many of the broken links I’m able to link directly to archive copies on the same day I made them and my archive snapshots were the only ones ever made.
I’ve been going through a number of broken links on my website and slowly, but surely, bringing many of them back to life. Thanks Broken Link Checker! Apparently there were 429 broken links, but I’m able to quickly fix many of them because as I made my posts, I backed up the original links automatically using Post Archival in the Internet Archive. (Somehow this plugin has violated one of WordPress’ guidelines and can’t be downloaded, though I haven’t seen any details about why or been notified about it.)