Here is a good writeup of some of the pros and cons of using a "reachability" approach.

https://blog.sonatype.com/prioritizing-open-source-vulnerabi...

>Unfortunately, no technology currently exists that can tell you whether a method is definitively not called, and even if it is not called currently, it’s just one code change away from being called. This means that reachability should never be used as an excuse to completely ignore a vulnerability, but rather reachability of a vulnerability should be just one component of a more holistic approach to assessing risk that also takes into account the application context and severity of the vulnerability.