Why do people run multiple Instagram accounts?

I'm trying to grow my Instagram account with FollowLiker.

I'm almost up to 7,000 followers, and get around 30-50 likes per post.

I'm wondering about how I go about ramping this up to the next level, and I see that people run multiple Instagram accounts, but I don't understand what the method is here? Do they have multiple accounts in the same niche, and then follow/unfollow people to build them all up, and then like/comment on the main account's posts? Or create new posts and tag the main account?

The follow unfollow and mention in their description,posts and dm the main account,

They use the other accounts to promote the main account either via DM or the link in bio or by mentioning it in each post.

Is no one gonna talk about my boy getting 50 likes on his 7k account? That's not even 1% engagement. OP needs better targeting and remove ghost followers.

And multiple accounts to shoutout main account that doesn't follow/unfollow