You fought a not-so-exciting war, where the biggest doomstack wins, it didn't matter which enemy planet you landed troops on and you could ignore building defenses if you were sure you were going to win in the end.

A 5k empire fleet wandering about you empire was an annoyance. Even with a bunch of transports it was only just promoting itself to a major annoyance.

Now though it's a serious threat you have to consider, transports or otherwise. You let that small fleet casually stroll about your empire, the enemy will have half your territory before you know it.

It wasn't very dynamic basically, whereas now you can lose planets and territory during the war.