wp_get_attachment_image(get_sub_field('hero_image'), 'full');
This will output the entire img tag w/ the srcset, so you do not need to include the img in your template.
<div class="wrapper">
<div class="wrapper2">
<?php echo wp_get_attachment_image(get_sub_field('hero_image'), 'full'); ?> </div>
</div>
If you need to add a class to the img, you can pass an array into the function (see: https://codex.wordpress.org/Function_Reference/wp_get_attachment_image).
<?php echo wp_get_attachment_image(get_sub_field('hero_image'), 'full', 0, array('class' => 'bilder2')); ?>
