A Russian T-72B isn’t a bad tank because it can’t defeat an equally aged Ukrainian Leopard 1A5. It’s a bad tank because it’s only useful between sunrise and sunset.
"…the T-72B is a terrible night-fighter. Its 1K13-19 gunner’s sight has a passive night-vision mode that doesn’t require an infrared spotlight, but it lacks range. To identify targets out to the tank’s maximum engagement range of around 1,200 yards, at night, a T-72B crew must switch on its infrared spotlight and use the 1K13-19 sight in its active mode.
The problem, of course, is that any enemy forces with their own infrared sights can see the spotlight, too—and pinpoint the T-72B’s position.”
"…the T-72B is a terrible night-fighter. Its 1K13-19 gunner’s sight has a passive night-vision mode that doesn’t require an infrared spotlight, but it lacks range. To identify targets out to the tank’s maximum engagement range of around 1,200 yards, at night, a T-72B crew must switch on its infrared spotlight and use the 1K13-19 sight in its active mode.
The problem, of course, is that any enemy forces with their own infrared sights can see the spotlight, too—and pinpoint the T-72B’s position.”