In #1184272: Remove deprecated $conditions support from entity controller we removed
entity_load_multiple(). Interestingly though, instead of actually removing it after it has already been marked as @deprecated in D7 we added a new method to
EntityStorageControllerInterface::loadByProperties() as well as another wrapper called entity_load_multiple_by_properties(). Additionally, this comes with another utility method named
->buildPropertyQuery(). So, to summarize: Instead of curing the problem with
$conditions we actually just moved it to somewhere else by introducing a new method as well as a wrapper, which, by the way is just a wrapper for
entity_query() itself anyways (which itself is a wrapper for the DIC)...
CMI currently has a custom work-around for this to bypass EFQ but once #1846454: Add Entity query to Config entities we should remove this stuff altogether and simply tell people to use EFQ for loading things by properties.