The tentacles can't move once they are restrained or within Pochita's effective range. Considering Pochita's extended melee range, they won't get close to his body to begin with, and even if they do, they will most definitely not hit him due to his mobility. Kaneki can hold him at bay, but it’s not an effective tactic to harm Pochita at all, it’s simply enough time to buy himself an opportunity to use the environment as a distraction.
Two problems with this.
For one, this argument operates under the assumption Pochita will restrain his tentacles, which you have not provided a valid reason as to how Pochita successfully tags Kaneki or his Kagune with the severe skill disadvantage he's at, as well as Kaneki's superior senses.
For two, Kaneki's kagune can extend up to hundreds of meters, range is not an issue. Even his first, smallest Kakuja produces tentacles that are incredibly large. Kaneki's kagune is not a set of tiny strings that will pelt Pochita from a few feet away, they are incredibly large and incredibly fast appendages that can bend and move in incredibly complex ways, should Kaneki will them. Kaneki's Kagune is a significantly more lethal weapon than some chains Pochita can flail around.
With his Kagune's range and flexibility that doesn't require Kaneki to physically move his body to direct them, he only needs thought, I'd say his mobility is even superior to Pochita's if he decides he wants to use his Kagune to fling himself around.
Pochita can simply overwhelm his senses by tricking him if too many things are happening at once. In the case of his body, he can throw his heart in an unknown direction (or towards Ken) to grow an entirely new body and launch a surprise attack
That's never going to happen. An advanced Ghouls' senses can track dozens of targets at once. Pochita lacks the limbs and the skillset to produce a number of variables capable of overwhelming Kaneki's sensory capacity.
Also, if he throws his heart at Kaneki, Kaneki is just going to crush it and kill him. That is the very, very last thing he wants to do, and I am confident Pochita would not willingly expose his ultimate weakness to an opponent with Kaneki's ability. We can both agree that even if he's not a combat god, he's not an idiot.
The main environment advantage Pochita gets is primarily speed, by hooking chains to swing from building to building faster than his original state of speed.
Lowkey, if Pochita starts swinging himself through buildings to build speed, there's no reason Kaneki wouldn't just copy that and do the exact same. He unironically has Technique Mimicry, and unlike Pochita, Kaneki doesn't need to waste movements to move himself—he can just direct his Kagune intuitively, and fight with both his Kagune and his normal limbs, whilst Pochita is stuck either without the use of his arms or without the use of a portion of them because of him having to swing himself manually.
The thing is, that version of Pochita and Quanxi have the same speed, one is not faster than the other. In referencing this, the same thing happening to Quanxi will happen to Kaneki, whose torso gets split wide open from the upper section. Plus,
Pochita is already skilled at counterattacking during acrobatic movements.
Okay, but that was not the point. The point is that if Pochita does not have a speed advantage, he cannot simply outspeed or overwhelm Kaneki's skillset and just waltz up to him and slice him in half. You focused heavily on the speed aspect of my response while failing to address the crux of my argument.
The thing is, Pochita has fought opponents on his level. He has been marked and killed by many of them, but he always rises and kills his opponents because he refuses to stay dead.
Lets stop you right here. If you're admitting that the reason Pochita defeated these opponents is because he simply refuses to die, then you admit that he did not use skill, or tactic, or clever thinking to defeat them, and simply continued to die until he won. Which would be correct, cause that's exactly what he did, but having you basically say it makes my job easier.
Okay, again, stopping you right there. Key words, off screen. We don't know what happened in any of Pochita's past fights, let alone against the Death Devil. You cannot equate this to martial mastery.
but Pochita literally excels in everything else,
He excels in LS. That's it. You've yet to explain to me how Pochita actually does the things you say he can do to Kaneki that Kaneki can do absolutely nothing to avoid.
Kaneki is a better fighter, he has better senses, he has better range, he can mimic Pochita's dubious mobility advantage, and his Kagune is inherently a superior weapon to Pochita's chains due to their flexibility and due to the fact that Kaneki does not actually need to move to utilize his Kagune.