An “influencer” is supposed to be someone who has the ability to influence people to do things. Whether they sell that ability or not has little to do with it.

Anyone with a big following of people who want trust them in some way is an influencer.

I mean, we don't call the Pope an influencer but we do Joel Osteen, we don't call Xi Jinping an influencer but we do Donald Trump, we don't call Satya Nadella an influencer but we do Elon Musk. It seems to be the dividing line between influencers is that they're using their influence for financial gain and that it's their primary asset. It doesn't have to be direct monetization but it has to be something where the motivation for them to influence is financial.

In the older definition, having a following that puts some stock into your opinions or recommendations is what makes you an influencer. (i.e. you don't become an influencer by being paid, being an influencer makes you interesting for companies to pay you to advertise)

Sometimes they aren't actually taking money. They are just shilling products so that other brands think they are paid to promote products and will actually pay them for the promotion.