I got a new iphone x and I am so cool.
Why did you get a new phone?
Because I want everyone to know how cool I am.
I see where you're coming from, but people should buy phones for their utility, not just for the brand. It's unfavorable to brag about things you own as well.
Why shouldn't I? Everyone else does.
You shouldn't stick it in everyone else's face that you buy expensive things because it shows them how shallow you are when you do it. Don't brag about things or no one will want to be around you.