The mw.inspect function is a part of mediawiki.base and is used as a shortcut to lazy-load the mediawiki.inspect module. I would suggest that this module is not used frequently enough to warrant this loading code being added to everyone's page views:
- Codesearch reports that the method is only called by the PerformanceInspector extension, as well as referred to in comments suggesting that it can be used for debugging
- A global search of JavaScript pages (link) revealed only a single mention, and that is in this userscript which appears to be a copy of mediawiki base.
Accordingly, I would suggest removing the lazy-load shortcut, in favor of suggesting that the module be loaded directly and then used