Yeah, I get what you're saying, I just don't think that's the case. Anybody that stands and bangs with Yoel f***ing Romero isn't afraid of anybody.
I think he's just dumb, especially compared to Izzy. I think he thought Izzy would just accept having his back against the cage because that's what he's used to in the octagon. The guys he has faced have been passive (Romero), just not all that good (Hall), or he had a massive size advantage (Hendricks). But Izzy stood his ground and chopped his leg down and he always had an escape path when he did start to get too close to the fence. When Costa did throw, Izzy was always out of reach because he has the reach advantage, is faster, and again had escape paths because he could easily read Costa. On top of that, Izzy was constantly feinting and faking and because Costa is dumb and just not that technical of a striker, he couldn't get a read on what was coming back at him or where his target was going to be. It's easy to say just bull rush him, but that shit doesn't work on guys as smart as Izzy.
I think you're underestimating guys like Khabib. Khabib is a f***ing savage, but he's not out there bull rushing guys. His striking 'isn't good' in the sense he's not winning a stand up fight, but he uses it very well to setup the take downs. He's very smart and not just some meathead like Costa.
I said it Sunday morning, but people aren't giving Izzy enough credit. He won that fight because he is on a different level than Costa and was always several steps ahead at all times. He's just that good. It's not that Costa was afraid or didn't have the right gameplan. He's just not on Izzy's level. And frankly, I think we all probably overestimated Costa to a certain degree.
If Costa wasn't afraid beforehand (I think deep down he was, but only he knows for sure), then something caught him early that hurt him differently than what he's felt in the past. You can have two reactions to that. Attack or retreat. Costa chose the latter. That's what I'm talking about in terms of his mental makeup.
Khabib will very possibly go down as the GOAT, so by no means do I underestimate his ability. He's unbelievable.
You say bullrushing a guy doesn't work on someone as good as Adesanya, but I'd argue prime Anderson was even more impressive and Chael put him on his back no problem, so it certainly isn't impossible.
If I'm not scared/intimidated, and a guy is picking me apart and busting my leg up that's gonna make me mad, and I'm gonna press forward, possibly even recklessly. If rather than anger my body responds with fear, I'm gonna retreat and essentially freeze mentally. That's what we saw.
I'm not discounting your point that Costa isn't a cerebral fighter, but a gorilla can charge forward and attack. Costa didn't because he was rattled.
I don't think we'll see it, but mark my words, if Weidman can earn a title shot he'll have Adesanya on his back in under 30 seconds.
It's very interesting, especially since there are some apt comparisons, but there weren't any great wrestlers at 185 for most of Anderson's reign, and unfortunately Adesanya's really faced none to date. Yes I know Gastelum and Romero, but both don't use it much and their preference is to stand.