Because some downloads may contain malware
How to Remove "Chromium" Malware: One Minute Solution!!!
You may be familiar with Google Chrome, but there’s another Google-affiliated browser you may not have heard of: Chromium. Chromium is the open-source alternative to Chrome and shares a large part of its codebase. Chromium’s browser engine is also used by other popular browsers such as Microsoft Edge.
Unfortunately, the Chromium browser is used for malicious purposes. Unless you download it from the Chromium project website, it may be bundled with malware and other dangerous content, making it impossible to remove. If you want to remove it, here is how to remove Chromium.
If you installed Chromium yourself (using a software installer), it shouldn't take much effort to remove it via the Windows Settings menu.