If you're thinking about scraping outside of Google or similar indexing engines, which is basically impossible, that's also not too useful

It's always under the radar of your competitors and everyone else. Just take a look at the backlink profiles using any tool or third-party services like Ahrefs or majestic keyword Explorer. You'll see a crazy amount of overlap in ref domains. It's just how the internet works – everything is interconnected.
So, whether you're a newbie or a seasoned vet, creating an everlasting, invincible link list just isn't gonna happen. That's why folks are always checking for live links daily.
As for scraping your own lists or buying one, that's totally your call. Either way, you're gonna face link list saturation. It's a common thing in the SEO world, so no sweat. The important thing is to just keep building those links.
Remember, sustainable link building and keeping those links active is key. It's a basic yet crucial part of the backlinking strategy