As someone who plays, this.
As someone who has been around music basically my entire life, he is. But don't listen to me, here are the voters from Rolling Stone:
https://www.rollingstone.com/music/music-lists/100-greatest-guitarists-153675/
"THE VOTERS: Trey Anastasio, Dan Auerbach (The Black Keys), Brian Bell (Weezer), Ritchie Blackmore (Deep Purple), Carl Broemel (My Morning Jacket), James Burton, Jerry Cantrell (Alice in Chains), Gary Clark Jr., Billy Corgan, Steve Cropper, Dave Davies (The Kinks), Anthony DeCurtis (Contributing editor, Rolling Stone), Tom DeLonge (Blink-182), Rick Derringer, Luther Dickinson (North Mississippi Allstars), Elliot Easton (The Cars), Melissa Etheridge, Don Felder (The Eagles), David Fricke (Senior writer, Rolling Stone), Peter Guralnick (Author), Kirk Hammett (Metallica), Albert Hammond Jr. (The Strokes), Warren Haynes (The Allman Brothers Band), Brian Hiatt (Senior writer, Rolling Stone), David Hidalgo (Los Lobos), Jim James (My Morning Jacket), Lenny Kravitz, Robby Krieger (The Doors), Jon Landau (Manager), Alex Lifeson (Rush), Nils Lofgren (The E Street Band), Mick Mars (Mötley Crüe), Doug Martsch (Built to Spill), J Mascis (Dinosaur Jr.), Brian May, Mike McCready (Pearl Jam), Roger McGuinn (The Byrds), Scotty Moore, Thurston Moore (Sonic Youth), Tom Morello, Dave Mustaine (Megadeth), Brendan O’Brien (Producer), Joe Perry, Vernon Reid (Living Colour), Robbie Robertson, Rich Robinson (The Black Crowes), Carlos Santana, Kenny Wayne Shepherd, Marnie Stern, Stephen Stills, Andy Summers, Mick Taylor, Susan Tedeschi, Vieux Farka Touré, Derek Trucks, Eddie Van Halen, Joe Walsh, Nancy Wilson (Heart)"
https://www.guitarworld.com/features/the-100-greatest-guitarists-of-all-time
He's only #5 there. Of course, I love Brian May, but he's not better than Hendrix.
There are many more professional ratings. I don't I've ever seen one without Clapton listed. But Kory knows more about playing the guitar than Slash, Eddie Van Halen, Gary Clark, Jr., Melissa Etheridge, Kenny Wayne Shepherd and so many more.