Yes, 5K followers is a popular account (see my definition of the types of influencers here). But …
Remember that the number of influencers is not the main thing you should focus on. Instead, focus on bringing your message to those influencers whose followers will absolutely CARE about what you do!
Think less about “reach” (i.e. how many) and more about INFLUENCE i.e. if that influencer can change behavior of their followers.
SMI* = Social Media Influencers