Trying to get all user ids from firestore database, so I can access the ratings and combine them,

import React, { useEffect, useState } from "react";
import { db } from "./firebase/Firebase";
import { collection, getDocs } from "firebase/firestore";
import { useAuth } from "./AuthContext";

const Ratings = () => {
  const { currentUser } = useAuth(); // Get the currently logged-in user
  const [userRatings, setUserRatings] = useState([]);
  const [userUIDs, setUserUIDs] = useState([]); // State for all user UIDs
  const [loadingRatings, setLoadingRatings] = useState(true); // Loading state for user ratings
  const [loadingUIDs, setLoadingUIDs] = useState(true); // Loading state for user UIDs

  useEffect(() => {
    const fetchUserRatings = async () => {
      if (!currentUser) {
        console.error("No user is logged in.");
        setLoadingRatings(false);
        return;
      }

      try {
        console.log("Fetching ratings for the logged-in user...");
        const userRatingsCollection = collection(
          db,
          "users",
          currentUser.uid,
          "ratings"
        );
        const ratingsSnapshot = await getDocs(userRatingsCollection);

        const ratings = ratingsSnapshot.docs.map((doc) => ({
          id: doc.id,
          ...doc.data(),
        }));

        console.log("Fetched User Ratings:", ratings);
        setUserRatings(ratings);
      } catch (error) {
        console.error("Error fetching user ratings:", error);
      } finally {
        setLoadingRatings(false);
      }
    };

    const fetchAllUserUIDs = async () => {
      try {
        console.log("Fetching all user UIDs...");
        const usersCollection = collection(db, "users"); // Accessing the users collection
        const usersSnapshot = await getDocs(usersCollection); // Fetching all documents

        const uids = usersSnapshot.docs.map((doc) => doc.id); // Extracting the document IDs (user IDs)
        console.log("Fetched User UIDs:", uids);
        setUserUIDs(uids);
      } catch (error) {
        console.error("Error fetching user UIDs:", error);
      } finally {
        setLoadingUIDs(false);
      }
    };

    fetchUserRatings();
    fetchAllUserUIDs();
  }, [currentUser]);

  return (
    <div className="container mx-auto p-4">
      <h2 className="text-2xl font-bold mb-4">Your Ratings</h2>
      {loadingRatings ? (
        <p>Loading your ratings...</p>
      ) : userRatings.length > 0 ? (
        <div className="grid grid-cols-1 sm:grid-cols-2 lg:grid-cols-4 gap-6">
          {userRatings.map((rating) => (
            <div
              key={rating.id}
              className="border rounded-lg p-4 shadow hover:shadow-lg transition"
            >
              <h3 className="text-lg font-semibold">{rating.itemTitle}</h3>
              <p className="text-gray-700">Rating: {rating.rating}</p>
            </div>
          ))}
        </div>
      ) : (
        <p>No ratings found for your account.</p>
      )}

      <h2 className="text-2xl font-bold mt-8">All User UIDs</h2>
      {loadingUIDs ? (
        <p>Loading user UIDs...</p>
      ) : userUIDs.length > 0 ? (
        <ul className="list-disc pl-6">
          {userUIDs.map((uid) => (
            <li key={uid} className="text-gray-700">
              {uid}
            </li>
          ))}
        </ul>
      ) : (
        <p>No users found.</p>
      )}
    </div>
  );
};

export default Ratings;

This shows the ratings for the items for the logged in user, but when I try to get user ids from all the registered users from firebase database, I get No users found. This is how the pathing is /users/mu2CXMasv4eBb4qxLYhs8mnKPty2/ratings/1

How the database looks like pt 1
How the database looks like pt 2

So how can I get all the user ids or combine all the ratings?

I tried aggregating and averaging ratings across multiple users in Firestore, querying /users/{userId}/ratings subcollections for community ratings.