1) Exactly what A. A. said
This: I don't know of any non-romance, contemporary indie YA that is doing really well (there might be, but I don't personally know of any).
2) First thing: YA is extremely competitive. It's one of those genres where authors see Hunger Games & Maze Runner & other big big hits and assume it's a big genre. It's not. However, it has loads of authors writing books for it, hoping to be the next Hunger Games.
3) Second Thing: YA Romance are the only books I've seen do well. Rest of YA fiction is very difficult.
4) All that being said, if your heart is in it, then you should do it. If you write something exceptional you'll do very well, regardless of the genre being a small, ultra-competitive one.
If your heart isn't in it, there are lots of genres that offer more upside and less competition, sometimes both.