...there are many limitations to movement and firing and they severely restrict the tactical element of the game
Those restrictions are where a lot of the tactical element comes from!
If I'm being attacked through a forest, I know that I can (relatively) safely get a Rocket Launcher to take potshots with instead of having to buy LAVs.
If the enemy is massing on the other side of a 2-wide border, I know that I can plug it up with cannon fodder while moving my real forces against another front.
If I've invaded an enemy and forests make the road through them the only way for a guerilla transport to kill my Bombers, I know I can safely stick a Tank on the road instead of having to garrison my capital.
If I hold Jorent on New Paradise, I know that my Bombers can pelt the enemy's Battleships with impunity because he needs a Naval Transport to get to me.
If the enemy invades a country that has a 1-wide, 4-deep canyon that ends in a dead end, then he'll have one hell of a time killing a Death Turret placed at the back end of it.
Just remember that the "tactical element" of the game is the struggle to both use and circumvent those obstacles, NOT seeing how many painful hurty things you can cram into one country in a single turn.
If you still don't believe me, go play a game on Emerald and compare whether you'd rather defend Predel or Gornaya or play on Antarcticus and tell me whether you'd rather try to hold Nova Polska or Pantherburg. Or better yet, go play the "Airbase" training scenario and concentrate on just how many options that desert gives you.