I've had this question posed to me a few times now, so I suppose I should address it...
1. Go read the chapter about being a writer, then tell your best mate to slap you with a fish.
2. Write cliche bad boy/good girl highschool romance. Include motorcycles, leather jackets, fist fights, and abssss.
3. Ignore #2. That was a joke.
4. But seriously, I got 1.5 million reads on the cliche romance while my serious writing struggles to get any. (*cough*go read Guardian Redemption and give me feedback pls*cough*)
5. What you should take away from this is that the most popular stuff on wattpad is usually .... not the best written. They're cliched out to the max, and they're almost always pure romance. There are a few gems that are popular, of course, but the chance of yours being one of them is slim. It could happen though!
But the point is that popularity means nothing. If you sent the popular writers to a serious critiquing site like Scribophile, they'd get eaten alive. I'M getting eaten alive over there, so younger writers who don't know the difference between an internal and external conflict? Maybe they're naturally gifted and don't need to know all the rules/guidelines of good story construction and can write something amazing on their first try. Most writers, myself included, aren't like that.
Don't worry about getting popular here. That will only help in stroking your ego. It won't make you a better writer. I think some ego-boosting is great for new writers (I probably wouldn't be here if not for all the baseless praise I received on my writing as a teenager on mibba (another writing site)). But after a while, it only holds you back. You'll think your writing is good, phenomenal, but once you start learning about what makes a story stronger or weaker, you'll start to figure out that old writing, the stuff that only got praise and never received a single criticism, that stuff is utter shit.
If you want to grow as a writer, don't harbor on the number of reads or likes. Don't crave the praise. You need honest, brutal criticism. On Scribophile, there's no such thing as a popular author. The culture is so different because everyone is focused on giving analytical, critical feedback.
I have no idea how to make it big here on wattpad. I don't consider myself popular. It's just my writing guide that gets a lot of reads, and that cliche romance (Stray), for some unknown reason. I'm really happy about the reads on the guide because that means people are growing and learning and becoming better writers because of it, so I'm grateful for that!
But I couldn't care less whether i have 20 reads or 200,000 on a story. What I do care about is getting detailed feedback. I'd rather have two comments that really pointed out big flaws in the story or characters, than a thousand comments saying "THIS IS AWSUM PLS UPDATEEEEEE!!!!1111!!!! <3333 XD XD"
Praise is definitely nice and makes you feel good, of course, but that's not going to help you long-term. If your goal is popularity, sell yourself out and churn out those cliche romances to your heart's content (if you legitimately enjoy reading/writing cliche romances, that's totally cool. Like I said, I have one too. I had no expectations of anyone actually reading it. I wrote it for fun.)
But popularity should not be your goal, not right now. Once you're published, hell yes you need to focus on marketing and popularity because that's how you'll get your paycheck. But right now, you guys are all still learning how to write a story, and popularity shouldn't fall into the equation. If it happens on its own, more power to you! That's an awesome perk!
But popularity shouldn't be the goal. Focus on becoming better writers.