> All people don’t want brands in their closed communities!

Since you can't avoid having these ads/brand placed in your preferred social media platform (the users are the product (to be sold to advertisers) and not the customers), the next best thing that you can do as a user is to subvert the undesired brands that you see in your social media stream (e.g. by posting something that makes fun of an ad that you see) to make the social media platform a less desirable place for the respective undesired advertiser.