Why aren't my rest responses being cached?

I created a simple rest endpoint to test caching and I see the response updating. What is stopping it from being cached?

Here's the rest endpoint code:

<?php

namespace Drupal\nm_base_api\Plugin\rest\resource;

use Drupal\rest\ResourceResponse;
use Drupal\rest\Plugin\ResourceBase;
use Drupal\Core\Cache\CacheableMetaData;



/**
 * This is just an example.
 *
 * @RestResource(
 *   id = "test",
 *   label = @Translation("Test"),
 *   uri_paths = {
 *     "canonical" = "/api/v1/test"
 *   }
 * )
 */
class Test extends ResourceBase {

  /**
   * {@inheritdoc}
   */
  public function get() {
    $response = new ResourceResponse(
      [
        'title' => 'test',
        'time' => time(),
      ]
    );
    $cache_meta_data = new CacheableMetadata();
    $cache_meta_data->setCacheMaxAge(2);
    $response->addCacheableDependency($cache_meta_data);

    return $response;
  }

}

And here's what I see in response:

$curl 'http://base.test:8020/api/v1/test'
{"title":"test","time":1651152255}

$ curl 'http://base.test:8020/api/v1/test'
{"title":"test","time":1651152256}

$ curl 'http://base.test:8020/api/v1/test'
{"title":"test","time":1651152257}