Armata is untested. Therefore it's "not good". T-34 was a great tank for its time, but it still had some "teething problems" so to speak. It has taken the designers and engineers a few versions to make it good. Likewise with AKs - what we usually call "AK-47" is actually AKM - modified version of the original design. Untested hardware will inevitably produce issues.

And no, being a tanker is very far from anything resembling safe. Not even if you're a NATO tanker, bulldozing civvies in the middle East. Much less if you are in an actual conflict with an actual military.