Most vulnerabilities are listed as: "allows an attacker to execute arbitrary code in the context of the current user". So it would seem that Edge is good at preventing elevated privileges.

However, I don't care at all about elevated privileges. If a bug in my browser allows code executing, that means that code is executing with my privileges. So all my data is already at risk. And my data is basically the only thing that's important. Becoming part of a botnet or the propagator of virusses is annoying at worst. Ransomware or my data leaking out is infinitely worse.

And Edge seems to exceptionally horrible at preventing code execution. Perhaps their security team should focus on that for a bit.