The disavow tool is one of those topics where the more you dig, the less clear-cut the answer gets. You'll find plenty of discussion in the major SEO forums, and opinions are all over the map - some swear by it for cleaning up spammy link profiles, others argue Google has publicly said it's rarely needed and can do more harm than good if misapplied.
Personally, I've had one site hit by a fairly aggressive negative SEO campaign. Ended up with about 2,000 domains pointing spam at it over a couple of months. After sifting through all of them in GSC's Links report, I only disavowed two. Just the ones that were actually showing up in the "Top linking sites" section and looked like they were driving any signal at all. The rest were either already ignored by Google or sitting on zero impressions. Throwing 2,000 domains into a disavow file felt like overkill - especially with the risk of accidentally dropping a legitimate link or getting the entire profile flagged as unnatural.
The tool isn't useless, but I treat it like a scalpel, not a sledgehammer. If you're disavowing en masse without checking what's actually passing link equity, you're more likely to introduce noise than fix anything. The fact Google themselves say it's a last resort tells you most people shouldn't be touching it.
