Well, I just reached over the 1000 sub mark and I've been posting there since May 2017. The people who reach 1000 in the first week aren't doing it by luck, they've achieved it by years of hard work, getting their names out there, collaborating with other artists, asking for feedback and striving to improve wherever they have a weakness. There are the rare comics out there that suddenly get 1000 subs immediately even if the artist is unknown, but it's the exception, not the rule.
As a whole, Webtoons does have a bigger used base, but it's hard to get noticed immediately because there is such a large volume of art being uploaded all the time. If you are making your comic purely to get noticed, then you need to maintain a regular update schedule, be very patient, use social media to your advantage, try to do a collaboration or art trade with other artists and, most importantly, put out the best art that you are capable of creating. If it's not good enough, practice, learn through videos provided for free on youtube or sites like Clip Studio that has a lot of great resources to help you.
The story that I share with my readers is my passion, but even if nobody subbed, that wouldn't matter. I love my characters and I love to draw. It makes me happy. I don't think you'll be happy with any sub number until you figure out WHY you're doing what you're doing. It's totally fine to have getting 1000 subs as your goal, but you can't be jealous of other people's seemingly quick success. You need to work very hard, it's not magic. It's practice, it's repeating motions thousands of times over, it's understanding everything from anatomy to perspective to how colours work together.
We all get agitated when we're criticized, but we need to take that criticism, learn from it and improve. We all need to be patient with ourselves and see how our art has grown rather than focus on how it's not as good as someone else's or that we're not as popular as someone else.
Anywho, that's just my two cents, and worth about as much as pennies in Canada now