I have a Wattpad account. I opened it years ago because I was curious to see what all the hype was about. I spent some time looking through what was on offer, I visited a few of the different forums and offered feedback... It was immediately apparent that there are very few talented writers to be found there. I did manage to network with a few people who seemed to be a cut above the rest and we did exchange writing samples and stay in touch for a time, but after a year or so that had run its course and it's been ages since I've been back.
I can't say that I went into it looking for anything particular. I like to read, and while everybody has their preferences, I'm not particularly averse to anything except poor writing. I wouldn't consider myself to be a fan of erotica or horror, but that's primarily because most erotica and horror is awful.
In terms of Wattpad, it would be easier for me to list what I DIDN'T like than what I did: Fan-fiction. It's nearly all tripe, badly written, unimaginative, tedious, unpolished doggerel... The amateur works of fantasy uploaded to Wattpad are reprehensible, but can on occasion provide a few good laughs - there were a few stories about wizards or werewolves or vampires or zombies that were positively hilarious because they were just so terrible... The romance was ghastly - tired, cliched nonsense...
Look at it this way, whether the site is free or not isn't really the point. If some knob were to set up a cart on the street-corner offering free food, I wouldn't go out of my way to eat it just because it happened to be free. Why slog through bilge when there are already so many wonderful books out there that you couldn't hope to read all of them in a thousand lifetimes?
Not to mention that probably better than 75% of the content uploaded to Wattpad consists of unfinished stories that are bloated to bursting with superfluous information dump prologues that haven't been proofread or edited or revised in any way, so it's rather unrewarding to scour the titles there in an attempt to find the one gem that might be lurking in that grave when one could just go to a bookshop.