Just saw your edit. One thing you should be doing is taking ownership of directories you plan to be working in. So for an external drive for example, you’d want to make sure your user(s) have r/w/x permission recursively (granting permission for all files and folders underneath using the same command) on the root folder of the drive then you can move stuff on and off freely.

I agree it could be more straightforward, but ideally you’d only have to do it one time when you first use the drive with that machine