IMO INF is mimicking the scope creep present in FS itself: Shivan fighters, then the Taranis, then the Lucifer, then the Sathanas, each time they show up with some AWESOME NEW UBERSHIP and each time you get some cool new weapon/beamz/subspace Macguffin/Bosch Beer to defeat it.
The latter half of FS2 breaks this pattern, which I
rarely see in games and which I think is the only appropriate choice when dealing with the Shivans as they were established. We don't defeat them - we run and hide, we stave off the danger, we survive but with the full understanding that if they show up again we could be utterly and completely ****ed.
But most games (including IIRC

's old plan for FS3) go the Inferno route: antagonists exist to be beaten, so the Shivans must be beaten somehow, which means we must get access to some awesome new weapon that negates the danger, which means that next time (and there's always a next time, because we all want to play more FS) the Shivans have to show up with a new, even greater threat. And so the scope creep continues.
The problem, gameplay-wise, is that there's a limit to how big a ship can get before the player can simply have no meaningful interaction with it in-mission. The Sath in Bearbaiting is pushing that limit. The Sol Gate with its glorious polygons is
definitely pushing that limit. The Shivan ships at the end of INF and the Gargant are well, well beyond it.