Why is there an “archive” icon on my file?

Of course. Here’s a clear explanation of what that "archived" icon means.

The "archived" icon on files in your company's SharePoint folder indicates that those files have been automatically moved to a cheaper, long-term storage tier by a company policy. This is done to save costs while keeping the files accessible.

Will it affect your use? For most daily tasks, no. You can still open, read, and download the files normally. The main difference is you might notice a slight delay (a few seconds) when opening them, as they need to be recalled from archive storage. You typically cannot edit the file directly while it's in this archived state; you'd need to download and edit a copy.

In short: The files are still there and usable, but your company's IT admin has set up this system to optimize storage costs.