If your comment has replies, you can remove the entire thread to keep work focused.
Steps
Find your original comment that has replies (a comment with ≥1 reply is a thread).
Hover it and click Three dot menu (⋯).
Choose Delete a thread.
A success toast confirms the deletion in the bottom left.
Click Undo within 10 seconds (or before you close the toast) to restore the thread.
Notes / Tips
Only the original commenter can delete the whole thread.
Each reply can still be deleted only by its creator.
If you open Three dot menu (⋯) on someone else’s comment, Delete is hidden.