I 100% agree with the bolded. He can be mentally very strong even when on the back foot (Tour 2024, although I disagree that dropping minutes on the toughest mountain stages was some historical feat, Amstel Gold Race last year, etc.), but he more often than not completely collapses when someone attacks him unexpectedly or his legs don't respond the way he thinks they will. Giro 2021, Vuelta 2023, LBL 2025, Tour 2025, this...he has to figure out how to avoid the collapse. He went to the 2023 Vuelta for example fully believing he would defend his 2022 title. Then Roglic attacked unexpectedly, he didn't feel great, and Vuelta over.
In the two major exceptions I can think of - 2024 Tour and AGR 2025 - I think there were big psychological factors at play. In the 2024 Tour, he wasn't expected to win. Pogi and Vingegaard were world beaters, he'd had a crash, it was his first Tour, he hadn't won the 2023 Vuelta, etc. In AGR 2025, he was newly back from an offseason crash, so the stakes were low.
When the stakes are high and he believes he should win, he seems to need 100% control and cannot handle the unexpected.
I don't think that is unfixable. He has the mental strength, he has physical strength, he has displayed it all at the same time, he can get there. But he needs to understand and accept the issue and embrace the work to address it. Step 1 is acknowledging that he has severely underperformed in stage races relative to his talent, expectations, and pay, and that responsibility for that sits with himself. Then dig into the why - OK, a lot of it is sudden collapses and highly variable performance. OK, what's driving that? And so on.