A page can be so hopelessly irreparable that the only solution is to blow it up and start over, i.e., create it de novo.
Copyright violations, extensive cases of advocacy, undisclosed paid sock farms, and extensive improper use of large language models are frequently blown up. Anyone can start over as long as their version isn't itself a copyright or WP:PAID violation, or a total copy of the deleted content.
Sometimes, the damage is beyond fixing. Although you can edit any page to fix the page content, you can't edit the associations and social history of a page, even if you delete every trace of that page on the wiki. Most often, this is common with perennial policy proposals that have been the subject of so much fighting that even a brilliant, earth-shattering work of genius would face significant opposition just because it's proposal #3941. And no, your version probably isn't a brilliant, earth-shattering work of genius. Your best bet under these circumstances is to let the fight go and let the perennial warriors blow each other up (or at least wear each other out) and try again later, if at all.
Sometimes, the damage is fixable but the effort in doing so dwarfs the effort involved in merely starting over.
This logic may also be applied to sections or parts of an article.
With articles, this is the TNT tipping point argument: if the article's content is useless (including all the versions in history) but the title might be useful, then delete the content to help encourage a new article. If you keep the article, then you're keeping something of no value until someone replaces it with something of value, when people tend to be more inclined to fill red links. When you see this as an argument to delete, don't give up. If you can repair the article in a timely manner, then you've neatly refuted that the article is irreparable. If you can't repair it in a timely manner, then this is the simplest argument to refute at WP:DRV; after all, they said it couldn't be fixed and you fixed it.
Deleting severely deficient articles through the WP:AFD process is grounded in established policy. According to WP:DEL-REASON, "Reasons for deletion include [...] 14. Any other content not suitable for an encyclopedia." Similarly, WP:ATD states: "If an article on a notable topic severely fails the verifiability or neutral point of view policies, it may be reduced to a stub, or completely deleted by consensus at Wikipedia:Articles for Deletion." Thus TNT might be invoked during AfD with caution: deleting articles for the purpose of cleanup can be contentious. The purpose of TNT is cleanup (to "start over"). Other relevant essays on this topic are WP:NOTCLEANUP and WP:Deletion is not cleanup vs. WP:Using deletion as cleanup (opposing views).