Most modern tanks can be pretty tough.
In fact, Tom Clancy recounted one such tale of an Abrams tank getting stuck in the mud during Desert Storm, deflecting shots from as close as 400 yards, and then surviving efforts to destroy it in place with just some sights out of alignment.
However, that toughness comes at a price. These tanks have a lot of blind spots.
What types of problems come from not being able to see through armor? Think about that scene with Welsh and McGrath during Episode 3 of “Band of Brothers” when they took out that German assault gun with a bazooka. Worse, the only way to really get a good view was to poke your head outside the vehicle. If the enemy has a good sniper, that becomes a dicey proposition.