Originally Posted by Ckamc
What makes me scratch my head is that both folders are the exact same size with the same content so I just don't understand why my phone needs double since it shows my storage at 17GB and want to free up some more space
Alright, think about it this way. Open your file explorer and check the size of either of the folders by looking at their properties. For instance, mine both show that they add up to 10GB. I've also got about 3-4GB of space being used for backups and my system partition, and even more for apps. So my guess? Probably using at least 20GB of my storage. Keep in mind that I have a 32GB phone. Now if I go to settings > storage, it shows that I have 12GB of free space, so it all adds up. If you do the math, I couldn't possibly be using 20GB total for both of those folders, so they have to just be different paths to the same location, and yours probably is, too.
My conclusion: if you delete one of those folders, nothing good can come of it. Look elsewhere and account for your system itself (I see you are using the stock firmware, which is quite large due to LG bloatware) and the apps you use. Check Settings > Storage and see what's using so much space.