Chromium-based Microsoft Edge browser with Microsoft Defender SmartScreen integrated, already protects users when they navigate to malicious sites or download malicious files, Microsoft today has expanded the Defender SmartScreen protection to “Potentially unwanted applications” (PUAs) downloads also in Edge Canary 79.

FYI, Chrome uses Google Safe browsing to protect you against dangerous sites and files, Chromium-based Edge browser uses Microsoft Defender SmartScreen for the same, you can notice the protection setting enabled by default under “Privacy and services” in Services in new Edge browser.
Note: Intentionally or accidentally switching the security setting off, causes Edge and Chrome to flag all downloads as malicious, so you shouldn’t be touching that, unless you know what you’re doing.
Chrome with Safe browsing built-in already blocks deceptive or unwanted software downloads, now Microsoft Edge also will do the same, to enable Microsoft Defender SmartScreen PUA support in latter
1. Ensure you’re using latest Microsoft Edge Canary 79.0.280.0 or later
2. Head to edge://flags page
3. Search for “unwanted”, in the highlighted results, for “Microsoft Defender SmartScreen PUA Support” fla,g select”Enabled” and restart the browser.

Note: The edge-SmartScreen-pua flag, when turned on, “will protect against downloading Potentially unwanted applications (PUAs)” on Windows and Mac.
Block unwanted App downloads in Chromium Edge
1. Now click on Ellipsis icon
2. Select Settings > Privacy and services, you’ll notice new option -“Block Potentially unwanted Apps”- that claims to prevent “downloads of low-reputation apps that might cause unexpected behaviors”, turn it on.