As for the "is armor obsolete" debate like most things it's complicated. As for pure combat power, nothing beats a MBT, but that also makes them the primary target for the enemy. The US combined arms strategy is designed to protect the mobile units as they attempt to break through and encircle the enemy, thus breaking supply lines and preventing enemy formations from being able to operate as fuel and ammunition runs out and they can be mopped up by follow on units. That hasn't change much and still has it's place. Seeing as how we developed these tactics based on blitzkrieg (as did the Soviets) it's well established doctrine. Tanks operated with infantry, artillery, and air support are extremely effective at controlling territory because of their mobility, firepower, and ability to communicate and coordinate.
Now on the modern battlefield there are more challenges, but as was touched on above, what sets us apart is our ability to see and engage the enemy. It's very, very hard to hide from thermal imaging tech and ours is light years beyond anything Russia uses. All that being said, sure it's easier to kill individual tanks, but formations of tanks used correctly will dominate most battlefields. Exceptions being urban, forest/jungle, or mountainous.
Full disclosure. I was a tanker.