I think he has become power shy. He isnt throwing that right hand to KO the opponent with the same regularity as before. Personally I think he has discoverd his pure boxing form and seems comfortable doing it. Listen, if he can KO you with a jab it means his power is still there. However he has become more of a boxer now and that may actually give him some longevity.
He should fight canelo, take the money and retire no matter the result. Any other option in my humble opinion is a mistake.
I went with slightly past prime. His redeeming clinic vs Alvarez and his stopping of a young hungry good prospect, even with a few hairy moments cements that opinion. He was legit hurt vs Yarde, but hardly exhausted, mentally or physically. I think his chin has slightly depreciated, which was never iron clad - hence the past prime rating.
I think we have to split prime/post-prime into physical and mental categories. I think his physical style ages well, fences from range, never relied on super speed or reflexes or volume. I'm not sure he's lost that much in this area. Look at his performance against Alvarez in the second fight, it was very sharp. But psychologically he's likely not the same after taking some big losses, so because of this he's not the same Krusher perhaps. Having said that, he showed good mental toughness in the Yarde fight, that can't be denied.
Clenelo taking a leaf out of the Manny Pacquiao book - wait til a former great fighter is looking past it, drain him, then get on as many drugs as you can. Only difference is Clenelo is pretty much universally despised within boxing circles while the equally repugnant Pacquiao is for some reason revered. ****ing horse****