Spectrum Holobyte came up with a decent tagline for its TANK M1 Abrams simulator/game in this ad from the June 1990 issue of Video Games & Computer Entertainment magazine... but the gap between "realistic" graphics and reality was still very, very wide at the time.
The PC EGA graphics were impressive at the time, with polygonal, outlined hills and flat topographical shading. But the look would be obsolete a mere five years down the road, as hardware-accelerated texture-mapped polygons became the standard, even on consoles.
No doubt the technical aspects of simulating the M1 were also very advanced. But then, as now, "realistic" usually just means "as realistic as we can get right now."