Ann Coulter is basically Milo Longlastname before Milo was a thing and he disgraced himself on that one podcast and exposed himself as a grifter to his own fans with the "White Privilege Grant" scam. Unlike Milo though, Coulter has managed to still be somewhat relevant in conservative circles.
The big difference also is that Ann Coulter is somewhat talented (don't shoot the messenger!) as a writer and comedian. Milo was a no-talent hack. I think it was even revealed at one point that all of his writing was ghost-written. He was the personification of the alt-right YouTube comments section, and that's it. He was never built to last.
Incidentally, I read (well, skimmed rather) some of Milo's tech articles from back when he was trying to be a real journalist. Not only do they sound like they were written by a completely different person (and if his newer stuff was ghostwritten, I'm sure much of that was too), but they basically bore me to tears and I felt like I was reading an old computer manual. I'm not that surprised our "Dangerous F****t" decided that being a full-time troll was a more worthwhile endeavor. As we see on this forum, going from serious contributor to unserious attention-seeker is sadly not that uncommon.