Admin center: display "cannot delete template" screen (show pages where template is in use) for a template used by about 22000 pages

taked 2mn 35s to display.

I am not sure it is very useful to display so much pages, as the goal of this screen is to let user swich pages' template so that the template we want to delete is no more used. If it used by 10 pages or less, we can image that the user switch template on a case by case basis, but with more pages, either he switches template from edit mode, page by page, or he bulk changes it for each all pages in a single operation.