Is there a word (noun or adjective) for: "Something you do not absolutely need in order to survive, but you do need (and it will enable you) to thrive"?
Any language will do...
Some of the synonyms below may be appropriate to thrive.
essential
ɪˈsɛnʃ(ə)l/
adjective
1.
absolutely necessary; extremely important.
"it is essential to keep up-to-date records"
synonyms: crucial, necessary, key, vital, indispensable, needed, required, called for, requisite, important, all-important, vitally important, of the utmost importance, of great consequence, of the essence, critical, life-and-death, imperative, mandatory, compulsory, obligatory, compelling, urgent, pressing, burning, acute, paramount, pre-eminent, high-priority, significant, consequential More
antonyms: inessential, unimportant, optional
fundamental or central to the nature of something or someone.
"the essential weakness of the plaintiff's case"
synonyms: basic, inherent, fundamental, quintessential, intrinsic, underlying, characteristic, innate, rudimentary, primary, principal, cardinal, chief, elementary, elemental; More
antonyms: secondary
2.
(of an amino acid or fatty acid) required for normal growth but not synthesized in the body and therefore necessary in the diet.
3.
MEDICINE
(of a disease) with no known external stimulus or cause; idiopathic.
"essential hypertension"
noun
noun: essential; plural noun: essentials
1.
a thing that is absolutely necessary.
"we only had the bare essentials in the way of equipment"
synonyms: necessity, necessary/essential item, prerequisite, requisite, requirement, need;
Isn't beneficial somewhere close?
desirable
enhancement
commensal/symbiote
agape
as in the love of all things extant and all thing past and all things to be.