TODAY tanks are being killed by both high end stuff and with IEDs. Tanks have been vulnerable to almost everything. Including advanced 5/6 kg tandem warhead sporting PG-7VR.
You are merely comparing different generations of Tank protections and Anti-Tank ammo. What you are not doing is comparing currently available Tank protection COMPARABLE currently available Anti-Tank ammunition.
Off course if you hit a modern tank sporting a modern armor and modern active protection against a first generation RPG or Milan you will see the Tank survive. But what you fail to realize is that even a lowly IED of a terrorist has gotten uprated in terms of explosive content and hardware, at least to the level that western tanks are being challenged. You can simply forget about putting up a Tank (even highly protected modern tanks) against smart ammo. The smart ammo already available, without restrictions in open market, for those who feel they need it, is enough to simply fry every human every equipment and any mission plan inside any tank.
You have to seriously sit down and start reading about beyond armor effect. Unless you do that you will never be able to admit that things do not look good for tanks.
Even in the case you cite of the Ukrainian civil war, the Kiev forces are simply surrendering hardware including tanks instead of having their mechanized formations strike out of the encirclements. This is the situation when only militia and partisans are fighting from the other side. Imagine what would a trained military like Russian Army do to the tanks that these idiots in Kiev put out.
If Kiev is making more tanks then it merely shows their idiocy. It proves nothing about desirability of having more tanks.
This link shows exactly how and how much the vulnerability is.
The British Challenger 2 Tank | TankNutDave