If you really think about it, you are being a total douche when you pray for anything
You are basically telling god... that you know what is best, more than god does
By praying, you are saying...
"Hey god, I know you don't want to give me a new car, but I want it anyway"
"Screw your perfect/divine plan god, I want a new car... me me me me me me, it's all about me"
If it is god's will... why are you trying to change god's will?
Do you really think you know better than god does?
Or, are people just selfish and don't care what god has planned?
Well people pray because basically they acknowledge that there's a supreme among everyone , God. Those reason why we pray is that we ask for anything. To ask for forgiveness, for intervention and much more. It is because our soul and conscience dictates us there's a divine one, that we must love