painlessness vs simplicity

painlessness and simplicity both are nouns.

Word	Noun	Adjective	Verb	Adverb
painlessness	Yes	No	No	No
simplicity	Yes	No	No	No

As nouns, simplicity is a hypernym of painlessness; that is, simplicity is a word with a broader meaning than painlessness:

Other hypernyms of painlessness include ease, easiness, simpleness.

painlessness (noun)	simplicity (noun)
The quality of being free from pain, without pain or trouble.	freedom from difficulty or hardship or effort
Ease; lack of difficulty.	lack of ornamentation
	the quality of being simple or uncompounded
	absence of affectation or pretense
	a lack of penetration or subtlety