为什么没有类似Monitor.EnterAsync的方法

using System;
using System.Threading;
using System.Threading.Tasks;

public class AsyncLock
{
    private readonly SemaphoreSlim _semaphore = new SemaphoreSlim(1, 1);

    public async Task<IDisposable> LockAsync()
    {
        await _semaphore.WaitAsync();
        return new LockReleaser(_semaphore);
    }

    private class LockReleaser : IDisposable
    {
        private readonly SemaphoreSlim _semaphore;

        public LockRe::aser(SemaphoreSlim semaphore)
        {
            _semaphore = semaphore;
        }

        public void Dispose()
        {
            _semaphore.Release();
        }
    }
}

public class Program
{
    private static AsyncLock _asyncLock = new AsyncLock();

    public static async Task Main(string[] args)
    {
        await using (await _asyncLock.LockAsync())
        {
            // 在这里执行需要同步的操作
            Console.WriteLine("Acquired lock");
            await Task.Delay(1000);
        }
    }
}