A shared enemy can imitate intimacy until there is nothing left to discuss.

Disliking the same person can feel remarkably like closeness. There is agreement, energy, and the pleasure of being on a side, and it can carry a friendship for a long time without anything else developing underneath. The connection is real and it is contingent on the opposition continuing.

Check what a friendship of yours would have left if the shared irritation disappeared. If the answer is little, that is not a reason to end it, but it is a reason to try building something else while you can. Introduce a subject that has nothing to do with the grievance, and see whether the conversation survives it.