Heavy MGs are very intimidating, especially if you’re new to COH. The Wehrmacht MG42 in particular can suppress Riflemen so quickly it often feels like you’re doing nothing but retreating against a skilled opponent.
Here’s a great illustration of how an MG can be defeated easily by using Riflemen garrisoned in a building to draw its fire. Everyone knows the “classic” MG flank, wherein one squad deliberately enters an MG’s firing arc so that multiple other squads can close in on the MG from other directions. Having a squad in a building draw fire is even easier, as you can see in this example on Sturzdorf.
You’ll notice how the Volksgrenadiers have trouble fending off Riflemen at close range, which is the optimal position for Riflemen when fighting Volks. Also notice how the garrisoned Riflemen take minimal damage from the MG, even after sustained fire — the long range and building defenses make a huge difference.