These positions are unpaid volunteer positions. Moderating more than a handful large subs is a full-time job.
There is a good chance that a proportion of these people willing to do an unpaid full time job that can direct the attention of a billion pairs of eyeballs have ulterior motives, or are indeed paid by third parties (companies, political parties, governments) to promote or censor certain news/memes/opinions.
There is a good chance that a proportion of these people willing to do an unpaid full time job that can direct the attention of a billion pairs of eyeballs have ulterior motives, or are indeed paid by third parties (companies, political parties, governments) to promote or censor certain news/memes/opinions.