Using the same partition for both Time Machine and other files Is it harmful or dangerous to the other files in the same partition as the Time Machine?

Because a lack of storage, every time the Time Machine backs up my Mac, it deletes the oldest backup. Is there a danger that the Time Machine is about to delete my other files in this partition?

These are my folders in the hard drive. You can see that there are some folders of the Time Machine, besides a folder of my files - Archive:
According to this HowToGeek article, as long as you don't put anything in the Backups.backupdb, you will be fine.
The Time Machine only deletes files inside the Backups.backupdb folder.
So your Archive folder and the files in it should be fine.
Relevant paragraphs from the HowToGeek article.

The easiest way to store files on your Time Machine drive is just placing the files on there directly. Plug in your Time Machine drive and open it in the Finder. You’ll see a folder named “Backups.backupdb”. Time Machine stores all its backup files under this folder. Just leave this folder alone and let Time Machine use it normally.
Place personal files and folders outside the Backups.backupdb folder. Don’t place anything inside the Backups.backupdb folder — Time Machine automatically deletes files and folders inside there to free up space, so you may find your personal files deleted if put them there.