Tanks are evolving, albeit slowly. Tank armour and protection systems have come a long way. However, cannons haven't changed much. Tank barrels have increased in diameter, with this trend continuing in the latest generation of tanks. However, the limit for practical round size has more or less climaxed. So what could be the next step to increase the lethality of cannons?
Firstly, let's look at why tank cannons are still relevant in the age of guided missiles.