EF attributes vs built-in C# keywords (like required). Differences and when to use?

class Foo
{
    public required int Bar { get; set; }
}

var f = new Foo(); // error

class Foo
{
    public required int Bar { get; set; }
}

var f = new Foo(); // error

using Easygym.Domain.Entities;
using Easygym.Infrastructure.Repositories;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Authorization;
using Easygym.Domain.Constants;

namespace Easygym.Api.Controllers
{

    public class UserController : Controller
    {
        private readonly IGenericRepository<User> _userRepository;

        public UserController(IGenericRepository<User> userRepository)
        {
            _userRepository = userRepository;
        }


        [Authorize(Roles = Role.Admin)]
        [HttpGet]
        public async Task<IActionResult> GetUsers()
        {
            var users = await _userRepository.GetAllAsync();
            return Ok(users);
        }

        [HttpGet("{id}")]
        public async Task<IActionResult> GetUser(string id)
        {
            var user = await _userRepository.GetByIdAsync(id);
            return Ok(user);
        }

        [Authorize(Roles = Role.Admin)]
        [HttpDelete("{id}")]
        public async Task<IActionResult> DeleteUser(string id)
        {
            var user = await _userRepository.GetByIdAsync(id);
            if (user == null)
            {
                return NotFound();
            }
            await _userRepository.DeleteAsync(user);
            return NoContent();
        }

    }
}

using Easygym.Domain.Entities;
using Easygym.Infrastructure.Repositories;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Authorization;
using Easygym.Domain.Constants;

namespace Easygym.Api.Controllers
{

    public class UserController : Controller
    {
        private readonly IGenericRepository<User> _userRepository;

        public UserController(IGenericRepository<User> userRepository)
        {
            _userRepository = userRepository;
        }


        [Authorize(Roles = Role.Admin)]
        [HttpGet]
        public async Task<IActionResult> GetUsers()
        {
            var users = await _userRepository.GetAllAsync();
            return Ok(users);
        }

        [HttpGet("{id}")]
        public async Task<IActionResult> GetUser(string id)
        {
            var user = await _userRepository.GetByIdAsync(id);
            return Ok(user);
        }

        [Authorize(Roles = Role.Admin)]
        [HttpDelete("{id}")]
        public async Task<IActionResult> DeleteUser(string id)
        {
            var user = await _userRepository.GetByIdAsync(id);
            if (user == null)
            {
                return NotFound();
            }
            await _userRepository.DeleteAsync(user);
            return NoContent();
        }

    }
}

using Microsoft.AspNetCore.Mvc;

namespace Easygym.Api.Controllers
{
    [ApiController]
    [Route("api/[controller]")]
    public class Controller : ControllerBase
    {
    }
}

using Microsoft.AspNetCore.Mvc;

namespace Easygym.Api.Controllers
{
    [ApiController]
    [Route("api/[controller]")]
    public class Controller : ControllerBase
    {
    }
}

using System.ComponentModel.DataAnnotations;

namespace Easygym.Domain.Entities
{
    public class User
    {
        public int Id { get; set; }
        [Range(1, 50)]
        public string Name { get; set; } = null!;
        [EmailAddress]
        public string Email { get; set; } = null!;
        [MinLength(8)]
        public string Password { get; set; } = null!;
        public string Role { get; set; } = null!;
        public DateTime CreatedAt { get; set; } = DateTime.Now;
    }
}

using System.ComponentModel.DataAnnotations;

namespace Easygym.Domain.Entities
{
    public class User
    {
        public int Id { get; set; }
        [Range(1, 50)]
        public string Name { get; set; } = null!;
        [EmailAddress]
        public string Email { get; set; } = null!;
        [MinLength(8)]
        public string Password { get; set; } = null!;
        public string Role { get; set; } = null!;
        public DateTime CreatedAt { get; set; } = DateTime.Now;
    }
}

 var passwordHash = BCrypt.Net.BCrypt.HashPassword(password);
            var user = new User
            {
                Id = Guid.NewGuid().ToString(),
                Email = email,
                Password = passwordHash,
                Role = role,
                CreatedAt = DateTime.UtcNow
            };

 var passwordHash = BCrypt.Net.BCrypt.HashPassword(password);
            var user = new User
            {
                Id = Guid.NewGuid().ToString(),
                Email = email,
                Password = passwordHash,
                Role = role,
                CreatedAt = DateTime.UtcNow
            };