Get list of webforms that can be created by the current user
I'll autoanswer my question :)

By grep-ing inside Webform source code I found that the permission name is not "create", but "submission_create", even if dpm($entity) is referencing "create".

$ grep -r "access" * | grep submission_create
webform_node.routing.yml:    entity_access: 'webform.submission_create'
Webform.php:                 if (!$webform || !$webform-&gt;access('submission_create')) {
(...)


So, this works as expected:

$entities = \Drupal::entityTypeManager()-&gt;getStorage('webform')-&gt;loadMultiple(NULL);
$forms = array();
foreach( $entities as $entity_id =&gt; $entity )
{
    if( $entity-&gt;access('submission_create', NULL) ) {
        $forms[] = $entity_id;
    }
}


It returns only the webforms that you are entitled to send submissions to.