You are not goin to get better by not writing, and on-line fiction has only one rule--it has to be gripping and hit the demographics just right.
Most on-line readers are not literary affecianados, and a lot of them also come from a different lingual background. I see stories that are outright grammatically and stylistically flawed gain traction and adoring fans, while more proficient stories don't get much reads if any.
The stories that do the worst are actually 'middle class' group, that neither appeal to the teen-on-cell-phone crowd, because the writers try to do a better job, nor they are towering masterpieces that win awards and/or can eventually be agented/push into trad.
Offer what you have to offer, try to figure out what you can fix, and if you enjoy the writing, write.