extravagance vs wastefulness

extravagance and wastefulness both are nouns.

Word	Noun	Adjective	Verb	Adverb
extravagance	Yes	No	No	No
wastefulness	Yes	No	No	No

As nouns, wastefulness is a hypernym of extravagance; that is, wastefulness is a word with a broader meaning than extravagance:

extravagance: the activity of excessive spending
wastefulness: useless or profitless activity; using or expending or consuming thoughtlessly or carelessly

Other hypernyms of extravagance include dissipation, waste.

extravagance (noun)	wastefulness (noun)
the activity of excessive spending	useless or profitless activity; using or expending or consuming thoughtlessly or carelessly
the trait of spending extravagantly	the trait of wasting resources
the quality of exceeding the appropriate limits of decorum or probability or truth