IServiceFactory.cs

using System;
using Microsoft.Extensions.DependencyInjection;

namespace ServiceFactory
{
    public interface IServiceFactory<T>
    {
        T GetService();
    }

    internal class ContainerServiceFactory<T> : IServiceFactory<T>
    {
        readonly IServiceProvider _services;
        public ContainerServiceFactory(IServiceProvider services) => _services = services;
        public T GetService() => _services.GetRequiredService<T>();
    }
}

ServiceFactoryServiceCollectionExtensions.cs

namespace Microsoft.Extensions.DependencyInjection
{
    public static class ServiceFactoryServiceCollectionExtensions
    {
        public static IServiceCollection AddServiceFactory(this IServiceCollection services)
        {
            services.AddSingleton(typeof(IServiceFactory<>), typeof(ContainerServiceFactory<>));

            return services;
        }

    }
}