Firstly you don't need someone who makes more than you to tell you the right way to lead your life, you should listen to someone whom you respect by leading their life the right way rather otherwise you're already leaning toward what you are avoiding.

Anyway among-st those I interact there are two sorts, one who like to define their lives via showing off (buy branded, post regularly on facebook to show off etc) and the ones who does what's right because they enjoy it but keep it on the down low.

Oddly enough the former are usually the "nouveau riche", they just made it like to buy tons of branded goods and show off, usually not that generous (both wealth & manners) and interacting with them is hollow. The latter of my associates are business people, they have properties, businesses, super cars mostly old money usually keep in their circles and interestingly do not post much on facebook except some business trips but more importantly talking to them you learn alot business experiences challenges etc.

If you feel that you need to step on people, degrade people or make 25k per month to join their clique I would say you might wanna consider changing your circle of associates.

Or you can take a trip to our nearby 3rd world countries and see how the less fortunate live, that might also give you a wake up call or rather bring you back to where you were before now.

Finally to answer your question no one does not have to be an ass to be successful but this is heavily subjective on the work environment, if you don't wanna be that guy consider changing that too.