it doesnt seem like its that popular. because im literally on the first page of top contributers with little ammounts of posts
First of all, you are not on the top contributor list. You cannot be on it with only 11 cycles.
Second, repl.it is more popular that you might find it. A lot of people use it all over the world. Plus, there is huge community that is creating new content and answering questions all the time. It has support in so many languages, which makes it a good choice in coding IDEs. Last but not least, it frequently holds competitions. These contests have increased Repl.it's popularity dramatically, and allow users to show off what they know.
All in all, Repl.it is very popular, and compared to its competitors, Repl.it is a really good choice.