Issue #3347873: Centralize permission checks in a service

core/lib/Drupal/Core/Session/PermissionChecker.php

+<?php
+
+namespace Drupal\Core\Session;
+
+use Drupal\Core\Entity\EntityTypeManagerInterface;
+
+/**
+ * Checks permissions for an account.
+ */
+class PermissionChecker implements PermissionCheckerInterface {
+
+  /**
+   * Constructs a PermissionChecker object.
+   *
+   * @param \Drupal\Core\Entity\EntityTypeManagerInterface $entityTypeManager
+   *   The entity type manager.
+   */
+  public function __construct(protected EntityTypeManagerInterface $entityTypeManager) {}
+
+  /**
+   * {@inheritdoc}
+   */
+  public function hasPermission(string $permission, AccountInterface $account): bool {
+    // User #1 has all privileges.
+    if ((int) $account->id() === 1) {
+      return TRUE;
+    }
+
+    return $this->entityTypeManager->getStorage('user_role')->isPermissionInRoles($permission, $account->getRoles());
+  }
+
+}