I'm sure lots of people try to gain an audience with a follow-for-follow strategy here on Medium too. And some of my followers are probably other writers who tried to play that game with me. But I've never done follow-for-follow myself. I think it’s a silly waste of time, at best.

It might even harm you.

As a writer, you want genuine readers who are interested in reading your words. But people who follow you just so that you follow them back are unlikely to read your stuff. And the algorithms that drive the whole platform here might take note of this. They might realize that, oh, look at this writer. He's got a bunch of followers, but none of them actually read him. So let's better not promote this writer since he doesn't seem to be capable of even getting his own followers to read him.

In other words, if you've got lots of followers who are not reading your stuff, that might be a signal to the algorithms here that your work is not worth promoting. Of course, you can't do anything if other people try to play the follow-for-follow game with you. All you can do is not reciprocate and thus discourage more to do the same.

Note: this is all speculation. I have no idea how exactly the algorithms here work. Only Medium does.