Although well protected from a frontal hit by the slopping armor, the sides have no slope. The sides have no active armor, but also, judging by the size of the mounting hardware they do not appear to be armored beyond rifle ammo. It appears this is light, cheap, fast and disposable.
The problem Russian main battle tanks had in Chechnya is that they were vulnerable from above and behind. This appears to be the case here also. They apparently made no effort to make the vehicle stealthy and I’ll bet all 800 hp is visible for miles in a thermal plume.
With modern anti-tank weapons, if you are armored enough to resist them, then you are too heavy to move, to heavy to cross bridges, and too heavy to transport by air. So you might as well scale back the armor to what will stop .50 cal and shrapnel.
I'm thinking the next-gen tank will be unmanned (controlled by somebody well behind it) but capable of serious firepower.