as it is, because
儘 centers on leaving things unchanged or following a state as it is, often with a sense of letting something be or acting in accordance with circumstances. The 'because' meaning extends from this idea of things being as they are and thus causing a result.
儘 combines 亻 (person) with 盡 (exhaust, use up), which likely contributes both sound and the idea of reaching a final state. The exact historical development of the meaning 'as it is' from these components is uncertain.
A person 亻 beside 盡 (exhaust, use up) suggests someone who has exhausted all options and now accepts things as they are, leaving them unchanged.
For ジン, imagine a person accepting things as they are while drinking a gin and tonic: gin -> ジン, and the relaxed acceptance matches the meaning.
selfish; egoist
unable to do (as one wishes); able to do only with great effort; almost impossible to do; beyond one's control; not always turning out as one wishes; not going the way one wants it to
unable to do (as one wishes); able to do only with great effort; almost impossible to do; beyond one's control; not always turning out as one wishes; not going the way one wants it to
whatever; never mind; I don't care; the hell with it
as one pleases
selfish(ness)