Yeah, sure and agree, the same situation when you want to download an Instagram image or whatever - you can if you know how to. But for a basic it may be a first aid and it takes much more time for those who want to copy/download.
Haven´t found a total solution for this, if any idea, share it, Paul, would be useful :-)
The right click prevention is a "wooden wall", but it is one step of many. I use the right click prevention along with a htaccess rewrite, redirecting any url requests ending in .jpg, .png, mp4, etc. to the home page of my site. Sure you can see the URL in the code inspector, but it will require the user to do even more work to access the file.