Jealousy, envy, and use-and-throw paper cups

I was wondering how the word "jealous" is thrown around easily like it's a use-and-throw paper cup. "feeling resentment against someone because of that person's rivalry, success, advantages, etc." Then again, resentment is "the feeling of displeasure or indignation at some act, remark, person, etc., regarded as causing injury or insult."

Isn't that too strong a feeling to be used casually? Or have we come to this stage?

Or is it used instead of Envy "a longing to possess something awarded to or achieved by another?"

Envy is not a word that was associated with a certain (and now mostly non-existent) Onida TV.

The quoted definitions have been taken from www.dictionary.com.