This is another potential way to do this.
There are many times this can be used, especially for things like trying to tell if someone is trolling on a 2nd account when their first got banned and things of the sort. However, this won’t always work.
Obviously, some people will already have both accounts made prior. And follower counts are not always the most accurate in terms of trying to test an accounts legitimacy. Non-streamers will tend to keep a low follower count, and some people (like I) tend to unfollow people if I no longer actively watch people, and keep the amount of people I follow low for my email’s sake.
But also, you may find people are actually legitimately new to the site. and using a bot that tries to prevent people from entering using methods like this may false flag these people, which will both turn them away as a viewer, and possibly other people as well.
While it wouldn’t be the worlds most challenging thing to code, I personally would rather leave a mod to make those decisions. A bot will either false-flag a person or miss something that a person might not have done.