Where the preferences files are stored varies widely by Application.
After you delete one of these files, the Application typically creates it anew, assuring you that any existing damage to the file is not causing your symptoms, and the file is correctly structured going forward. So if you look EXACTLY where you saw it before, the newly created file will be there.
Its presence or absence is not the cause of problems nor the solution. If it is DAMAGED, as implied by specific symptoms you are seeing with a particular Application, removing it and allowing a new, correct one to be created, sometimes solves specific problems.
Deleting preference files without a specific direction in mind is a good way to bring your Mac to a standstill. So if you want to pursue solving problems (by deleting preference files or any other means) please describe the problems you are having, and the Applications that are giving you these problems.