Not having globals at all or restoring them on reload isn't exactly "don't need anything complicated for this", especially considering using a generic hot-reload tool on AAA 5M+ LOC projects.

There's no easy way to retrofit hot-reload into these large codebases. Sure, it's easier if you design everything up-front with hot-reloading in mind, but it's still going to be hard to convince developers that they cannot use globals, thread-local storage, function statics, or other inherently stateful things that just won't work with DLL reloading.