It's like 1% luck, 99% effort. I think the best way to think of the luck based aspect is through recommendations.
Say you don't work hard and there's not a lot of chapters or interesting art /story etc and your comic gets recommended by some popular person or even word of mouth. The people it is recommended to will glance, find it boring, and leave. You won't even know they existed, you'll just notice your numbers never go up anymore.
Whereas if you had a draw, something cool, interesting marketing that recontextualised your characters allowing the audience to connect to them from a fresh perspective for example. You'll find that every recommendation retains more people, who are staying cause there's a great backlog of content or Interesting character/story.
The luck just doesn't become valuable until the work is high quality enough for wider appeal in some way.