Getting Error when trying to return users from DB

It's been 3+ hours and I can not for the life of me pull users from my Users table using a DB:: query.

My goal is to display the number of Users following all Competitions for a given Confederation. So basically all Users under a specific Confederation.

My function is here:

public function users() {

    // grab all competitions under this confederation
    $compIDs = $this->comps()->select('id')->where('confederation_id', '=', $this->id)->get();
    // loop through all competitions and grab the user IDs from the users_competitions table
    $userIDs = DB::table('users_competitions')->select('user_id')->whereIn('competition_id', $compIDs)->get();
    //  grab all the users from the users table by their id
    $users = DB::table('users')->select('username')->whereIn('id', $userIDs)->get();
    
    return $users;
}

When i call it, i receive 1 of 2 'errors' (depending on the various 'fixes' I have tried): 1. an empty array for $users (there should be a SINGLE match currently); 2. 'object of class not be converted to string' error.

My database consists of the following tables:

Confederations (primary key: id) Competitions (primary key: id, foreign key to Confederations: confederation_id) Users (primary key: id) Users_Competitions (pivot/relationship table) (foreign keys to Competitions / competition_id and Users / user_id)

I have the following models:

Confederations Competitions Users (no model for the pivot table)

I was originally hoping i could perform a hasManyThrough relationship from the Confederations Table -> Competitions -> Users_Competitions -> Users, but i was unsuccessful in finding a way to do this.

This seems like it should be VERY simple but i can't for the life of me figure out what i need to do nor what i am doing wrong. I am very frustrated.