LinkedIn groups come in all variety of topics. Think of them as think tanks, or silos, of similarly-interested experts you can draw from and contribute to.
Belonging to one or more is a choice. That carries responsibilities.
Not participating is not a very business-like decision. After all, you don’t earn a business reputation by always watching. You have to be in the game.
So if you joined groups on LinkedIn that don’t work for you, or whose purpose no longer applies to you, drop out. It’s easy.
On the other hand, if you have something meaningful or insightful to add to the group, answering questions and adding articles you read of common interest. Please do so, professionally and intelligently, as often as it is needed. You decide how much and how frequently. If you have experience in your field, the frequency will be a direct reflection on your expertise.
And it’s a two-way street. It’s OK to ask questions in the group no matter how much an expert you think you are. Poll the group. Gauge the feelings about a hot topic by asking open-ended questions.
Be a recognizable, respected group participant. No one dances with a wall flower.