This feature was voted #45 on the 2022 Community Wishlist Survey.
Problem: Edit counts are hard to determine unless you know about external tools and user scripts that show this information, or if you explicitly state how many edits you have on your userpage. Attempting to paginate through a user's contributions to count their edits can take a very long time if they have a very high edit count.
Proposed solution: Show a user's edit count at Special:Contributions, similar to how it is done on mobile web.
Note that some discussion around this in the past has been to introduce a new magic word; this feature is not that.