deleting multiple empty photo albums

You can select many albums at once, if you are in the Albums view in Photos then you can drag a selection rectangle around the thumbnails of the albums.

Then you can directly ctrl-click or right-click the selected set of albums and use "Delete ... albums" or drag them to the folder.

For example - dragging a selection rectangle across the albums:

Deleting all selected albums together by ctrl-clicking them:

My screenshots are from Photos 6 on macOS 11 Big Sur. Which system version do you have installed?

Create a new folder and put all of the empty albums in that folder. When you delete the folder it will also delete the albums inside:

In big sur, I can also select multiple folders as shown above by Leonie. I thought the behaviour was the same in Catalina.