Depends on the site.
On Wattpad, most of my subscribers don't read my stories (for the past few years, the view count only changes when I edit), so I'm pretty sure they're bots. If one of those happens to drop off, I don't care.
On Tapas, it depends. There was one subscriber early on who seemed to want me to read and subscribe to their series, but it didn't interest me. ^^; They unsubbed pretty quickly. I think most of my other subs here subscribed to my story as a possible bookmark for later and aren't actually reading it, so if they eventually do and find out that it's not their style, that's understandable.
The other site I post to, Royal Road, there's no way for me to check the accounts of the people who are following me. Ironically, that makes those followers feel more real. There's no possibility that they're following just to get me to check out their own work. It's also harder for me to get followers there. So, when one of those followers unfollows, like what happened a few days ago, that actually makes me a little self-conscious about what I did wrong.