I’ve done a few FOBs, marine squads, HVTs, etc. From what I can tell, they’re all the same as one another (e.g., all bases are reused assets with identical objectives) and don’t have any story or narrative tie-in. I’ve also noticed that the purple areas seem to reuse assets as well, don’t have story beats, and have only been differentiated from one another by Weapon background dialogue talking about prisoner processing or repair bays, etc.
I understand they give you some bonuses. Beyond getting gun variants or vehicles that are largely only useful for clearing more FOBs and HVTs (since you go on the rails for main missions and those power weapon variants will only last until you run out of ammo), is there any reason to keep doing these side missions? Is there an eventual story payoff of some kind?