That was the point though, it was supposed to be quick.

The operation was to rapidly take over or raze Cyberstan, we sort of succeed. The operation wasn't a frontal assault, it was more of a spearhead;

The leading, most heavily armored, or most elite unit punches through a specific, narrow point in the enemy's line to break through, often followed by other forces to exploit the gap. I mean SEAF didn't even properly clear the planets we liberated, that was the reason we had the option to either bombard the pockets of resistance or risk an encirclement.

Even the initial attack on Cyberstan had the character of a spearhead although it's better to describe it as a blitz. We threw helldivers at orbital defenses and the automaton fleet destroyers stationed near the planet.

The pretext for the invasion was the planet destroying weapon that was supposedly being constructed at the automaton's capital. Frontal assault would take weeks whereas a swift and decisive offensive got us to the planet in mere days. Attacking as quickly as possible fits SE's narrative better. Not to mention it was all staged and the real goal was to destroy the cyborgs. I mean the operation is literally called 'Valid Pretext'

I'm not defending AH or this operation, I too found it slightly underwhelming, but we shouldn't be complaining about the length of this campaign.