A delete button per scene on the scene browser or in the package manager would be the same workflow, unless you could select more than 1, which you can't on any. Not sure why you need to load a scene unless it's to remember what it is like, but this loading is the slowest part of the process for you then, and no delete button would help anyway.
Deleting in VAM is doable with a few VARs, but from 10 onwards the best place is using a file manager for maximum flexibility. A suggestion is to use ALT+TAB to check the VAR's name in the Scene Browser and delete it with a file manager, easy.
If you have a lot of VARs in your AddonsPackages you might want to look at some programs here that manage these, show thumbnails of the scenes like the Scene Browser does, etc. I opted for a manual approach and created subfolders in AddonsPackages like Looks, Plugins, Clothes, and moved the respective VARs into those. To VAM this makes no difference, but now I know what is what, new VARs get downloaded to the file-free (subfolders only) AddonsPackages, and there I can decide if I want to keep them - and move to the subfolders - or if I can delete.
Back to the delete button topic, own scenes can be deleted easily because they're just 1 file, but a VAR can have scenes and a lot more in it. Deleting only a scene from inside a VAR is likely a much more difficult implementation, and would then change the benefit for the VAR referencing and version control. If you remove or add something to xxx.mypackage.1.var then the Hub's xxx.mypackage.1.var is not the same as yours. If this is a dependency of another package and you removed something in it that is needed for the other, then there's errors and problems.
A VAR can have several scenes, it's for you a lot more work to get them all than deleting the VAR. Another suggestion, there's a hide button, this will help you tidy the Scene Browser without changing the VAR, if you want to keep it that is.
In a nutshell, it's not as simple as just adding a delete button.
