That's a stupid argument. Khabib and Javier had said that Islam took rounds off Khabib in sparring and so many fighters have said that the guy they look up to is better than them even when it turned out to be quantifiably untrue. You gotta be like 15 to use that as part of your fucking argument at this point.
Hard to say who's better, Khabib might be the most overrated fighter in MMA history...He was great, fringe top 10 all time but his resume is thin and the idea that he was some unstoppable monster just always felt a bit hyperbolic to me, if he fought guys like Islam, Arman, Bendo, Burns, Khabilov etc. I think youd have seen him struggle and have closer fights similar to the Tibau fight. He just fought very few guys that could grapple at a decent level, let alone wrestle at all that were high level fighters so his strengths just crashed through guys weaknesses. He didn't look too good vs Al I'Aquinta surprisingly.
Anyways, Id still probably favor Khabib to beat Islam but anyone acting like it's an easy fight or a forgone conclusion...I'm weary of. Khabibs chin seems WAY more reliable and even if his cardio seems better to be honest...which I think would play a big factor. If Islam had more power in his strikes, it'd probably sway me but I think Khabib would crash into grappling range even if getting caught and force a serious pace, take away space and it make it his fight. That said? Islam has beaten the better opponents that this point probably and if he defeats Arman/Topuria, definitely. To me it's a 60/40 type thing, they're on each other's levels for sure.