The most savage thing a person can do organizationally is behind closed doors start spreading a "what does X team really do anyway?"

Easy to spread that vibe, hard for the team you're throwing shade on to refute it.

Not questioning whether they're doing important work, but whether they're doing it well.

"They seem to have less output than I'd expect. How hard could it possibly be? If I were them I would simply do X. I think they're making excuses for their lack of ability."

Needless to say, I do no think it's a legitimate tactic to spread this kind of unfounded FUD.

In an organization you must defend against this possibility by making sure that everyone can see that your group is clearly producing more value than the political capital (e.g. headcount) it is spending.

The best way to counter such a vibe is to let it never get going in the first place.

If you don't defend against this, your team is on the path to death.