and so on vs etcetera

and so on is not a noun while etcetera is a noun.

Word	Noun	Adjective	Verb	Adverb
and so on	No	No	No	Yes
etcetera	Yes	No	No	Yes

As adverbs, and so on and etcetera are synonyms defined as:

Other synonyms of and so on include and so forth, etc..

and so on (noun)	etcetera (noun)
	additional unspecified odds and ends; more of the same; entity, other pronoun; pronoun, entity; quantifier: other

and so on (adverb)	etcetera (adverb)
continuing in the same way	continuing in the same way