Better alternatives to random_device in C++?

I have been using random_device rd{} to generate seeds for my Mersenne-Twister pseudo random number generator mt19937 RNG{rd()} as have been suggested here. However, it is written in the documentation (comment in the documentations' example code), that "the performance of many implementations of random_device degrades sharply once the entropy pool is exhausted. For practical use random_device is generally only used to seed a PRNG such as mt19937". I have tried testing how big this "entropy pool" is, and for 10^6 number of calls, random_device returns me more than 10^2 repeating numbers (see my example code and output below). In other words, if I will try using random_device as a seed to my Mersenne-Twister PRNG, it will generate a solid fraction of repeating seeds.

Question: do people still use random_device in C++ to generate seeds for PRNG or are there already better alternatives?

My code:

#include <iostream>
#include <random>
#include <chrono>

using namespace std;

int main(){
    
    auto begin = std::chrono::high_resolution_clock::now();
    
    random_device rd{};
    mt19937 RNG{ rd() };

    int total_n_of_calls = 1e6;
    vector<int> seeds;
    
    for(auto call = 0; call < total_n_of_calls; call++){
    int call_rd = rd();
    seeds.push_back(call_rd);
    }
    
    int count_repeats = 0;
    sort(seeds.begin(), seeds.end());
    for(int i = 0; i < seeds.size() - 1; i++) {
        if (seeds[i] == seeds[i + 1]) {
            count_repeats++;
    }
    }
    
    printf("Number of times random_device have been called: %i\n", total_n_of_calls);
    printf("Number of repeats: %i\n", count_repeats);

    auto end = std::chrono::high_resolution_clock::now();
    auto elapsed = std::chrono::duration_cast<std::chrono::nanoseconds>(end - begin);
    printf("Duration: %.3f seconds.\n", elapsed.count() * 1e-9);

    return 0;
}

The output:

Number of times random_device have been called: 1000000
Number of repeats: 111
Duration: 0.594 seconds.