When it comes to describing the indispensable aspects of something, "essentialities" is indeed a fitting term. However, there are several other synonyms that can be employed to convey a similar meaning. One such alternative is "necessities", which emphasizes the crucial elements required for a particular entity or concept. "Fundamentals" also serves as an appropriate synonym, highlighting the basic principles or core elements that are inherent to a given matter. Another similar term is "essentials", which underscores the vital components that cannot be overlooked. All these synonyms serve as effective substitutions for "essentialities", enabling us to articulate the indispensable aspects of a subject with ease and clarity.