nice work man in bringing a raw page to 99 pagespeed. As you are letting bloggers pace their own ads, this will kill your scores. Today my own website cmoowls.com hit an LCP of 5.8s with a score of 70. But the LCP element was just a line of text, not an image.

The proble, was the element render delay. The first frame actually arrived after the load even, so our analytics already had started loading. Lighthouse counted this in the LCP and it was bad. Then. I fixed this by loading analytics after first paint instead of on loading. And then the next three runs gave me 99, 99, and a 100 (LCP 1.8, 1.8, 1.7).

But one small point here: CWV usually comes from Chrome's 28 days of visitors. 99 is just a lab score.