Modern warfare is not confined to firing missiles and drones or heavy bombing with fighter jets. It’s much more than that. Achieving dominance in other domains, in fact, plays much more crucial role in the battlefield. Iranians have not faced the actual war just because Iran's opponents (i.e. US and Israel) could not afford to launch a full-scale war against Iranian forces, primarily because they were unwilling to take obvious risks involved in the actual ground war. Despite heavy aerial bombing by US and Israel and vast destruction, Iranians could not be forced to give in. That provided Iranians with an opportunity for claiming a 'victory' over their enemies and thumping their chest. This was not even a full-scale war; rather it can be regarded as a shallow war.
During a typical conventional war, ground forces try rapidly moving their tanks, artillery, and other weapons to outmaneuver the enemy and use these weapons for devastating effect. However, one of the most crucial aspects in a conventional war is to draw the war plans, test, refine, and practice these plans in the peace time and best use them during the war. An military commander able to outmaneuver the enemy can easily offset enemy's quantitative and, to an extent, qualitative superiority on the battlefield. Iranians have not faced such a challenge in their war with the US and Israel. However, if the performance of Iranian IRGC in Syria can be used as a yardstick, one can easily say that Iranians suck at the conventional military skills.