[2023] Unable to delete old cloud saves

If this is the Steam edition you can see your cloud saves here:

Sign In

store.steampowered.com
But so far as I know they provide no way of deleting them, nor of even seeing how much free space you have there.

I did find this though:

Step-by-Step Tutorial on How to Delete Steam Cloud Saves - MiniTool Partition Wizard

Have you enabled Steam cloud sync in Steam application? Do you know how to delete Steam cloud saves? Here is a step-by-step tutorial which might be helpful. www.partitionwizard.com
Does that work for you?  

I've never used that process myself, but I guess Access Denied either means you need to ne Windows Admin to do it, or that folder does not actually exist. Can you see it?