Rezeki = Credited Luck or lucky.

It is not specific to wealth alone. If the fruit tree suddenly gave you bumper harvest, its rezeki. Someone gave you used clothes/ furniture that is still good to to wear and use, its rezeki. You won free stuff or food, its rezeki. So it is luck.

You might argue there is another word for luck that is tuah. But if you make words out of it.

A : Wah! Bertuah la kau tahun ni!
B : Rezeki la katakan...

Also rezeki somehow cannot be chained with bad happenings. Like if you escaped from death. I don't think anyone would say "Rezeki aku
sebab tak mampus lagi!"