Log4shell was a good example of a relative strength of .NET in this area. If a comparable bug had happened in .NET's standard logging tooling, we likely would have seen all of the first-party .NET framework patched fairly shortly after, in a single coordinated release that we could upgrade to with minimal fuss. Meanwhile, at my current job we've still got standing exceptions allowing vulnerable version of log4j in certain services because they depend on some package that still has a hard dependency on a vulnerable version, which they in turn say they can't fix yet because they're waiting on one of their transitive dependencies to fix it, and so on. We can (and do) run periodic audits to confirm that the vulnerable parts of log4j aren't being used, but being able to put the whole thing in the past within a week or two would be vastly preferable to still having to actively worry about it 5 years later.
The relative conciseness of C# code that the parent poster mentioned was also a factor. Just shooting from the hip, I'd guess that I can get the same job done in about 2/3 as much code when I'm using C# instead of Java. Assuming that's accurate, that means that with Java we'd have had 50% more code to certify, 50% more code to maintain, 50% more code to re-certify as part of maintenance...