You don’t have to announce your exit from a toxic group. Just stop showing up and let the silence explain.

Leaving quietly is a legitimate option, and it removes the argument entirely. Announcing a departure invites a conversation you did not want, with people unlikely to hear it, and usually hands them a story about you to pass around afterwards. Absence gets understood well enough on its own.

If a group has become a cost, start by going less and replying less, then stop. Keep the individual friendships worth keeping by contacting those people separately. You owe an explanation to the ones you actually care about, not to the group.