Both are based off Chromium, so security wise they are more or less equal. As it has already been stated the Edge browser has Smartscreen, which is very good. Personally with the Edge browser, you really only need an ad blocker, as Smartcreen is essentially your web filter. You could add another like Malwarebytes, Emsisoft, etc...if you feel like you need more, but IMHO Smartscreen is sufficient. If you turned on Network protection via Configure Defender, that's kind of a web filter in a way if I'm not mistaken, but Smartscreen in Edge will do the heavy lifting.
When it comes to patching, Chrome may be ever so slightly faster, but I can safely assume that Microsoft would apply those security patches very quickly, so I don't think you would be left vulnerable for very long.
both should be great honestly. the real question is will both limit adblocking or just google chrome.
From my understanding the adblocking issue pretty much applies to Chrome only, but it will become part of Chroumum, thus affecting other Chromium based browsers. Google did state however, that 3rd party browsers such as Edge can do their own thing if they want, meaning they don't have to follow Google when it comes to Manifest 3.