Doing it, lol. XD But seriously, I guess it'd be the promotion since social media algorithms are the work of the devil.
Time
Everything takes so long to draw. Everything takes so long to post to account for said drawing. Every normal prose chapter of a story becomes a year or two-year endeavor ;___; I just want to show my story at a good pace man, but the flesh is weak.
Time and marketing, mostly marketing.
I've seen people make epic detailed comics with little to no buffers and the ability to post more than once a week. Idk how they get time for that.
Marketing is just a whole can of confusion. You pretty much have to market the site you're marketing on. I feel like the only site I get noticed on is Instagram, but that's not saying much. Anything I post on tumblr disappears into a void, facebook isn't popular anymore, and twitter caters to controversial politics.
Oh yeah! Lacking time, soon-to-be followed by the one and only "Sorry, work is keeping me from posting steadily" banner. I relate. >.>
I believe, though, that if the audience truly is interested, they don't mind waiting for a (year, cough) month to get to the next episode. I mean, speaking from personal experience here, but most people I deal with are just happy my mate and I are back to posting something, even if regularity is nowhere to be found. 
I'd have to echo the Time sentiment. It just takes a huge amount of time, and it never feels like you can stretch it out enough.
Also I'd add the space in between pages. Once I finish one, even though I've got an outline and I know what to do next in the story, figuring out how it's supposed to look on the next page is very tough for me.
They might be, but I mean in a 'reveal cool thing' standpoint. With the western comic inspiration I just get antsy to post my own scenes that don't exist because I keep thinking about how much I've polished and that readers might like it as much as I do. One example that comes to mind is revealing the villain of the comic to begin with - gotta buckle up and draw if I want that shown within the year, but I want it noooooow
Ohh, as in "hitting a milestone moment in the series"?
I cannot relate to that with my comic, because it's made of one-strip stories and scenes. However, I can see where you're coming from. Time might be tricky to deal with when you're trying to build an atmosphere towards a climax (if I understand the comment correctly). Delays may harm the power of the climax you intend to build, indeed.
It makes me think, perhaps that's why TV series sometimes add a "Previously on blah blah blah show". They want to keep the upcoming climax up and going.
Yup, that's it. And if you're already on sketch phase ahead of time, you just want to skip all the way to that spot, but schedule and routine is important to not get confused. A Previously On is good for shows but in here it's best between large chapter breaks, or someone binge reading might just be seeing redundant pieces.
I used to do a 'Previously On' dialogue box for each page release I did when exclusively on Instagram. It was a huge time consuming hassle
That's fair. Honestly unfamiliar with the climax issue, so not sure how to provide feedback. Have you thought of anything to keep it all up and going without any "loss of steam"?
Really? Were they happening between chapters (aka, several strips/pages/stuff) or before every page/strip? You'd think it's not so time consuming considering it's mainly "cropping-pasting panels from previous pages". :0
@Birbmagadon it was for each chapter since I gained new followers with each release. The dialogue box was on each intro splash page, which dropped every two weeks. The reason it was a hassle, was the program I used to make it was a pixel art program called Aseprite. I had to write each line and drop it into order. (That and I was a total beginner at comics xD)
Oh hell, I see the struggle then haha. Have you considered doing it again now that you know how to edit/add fonts/etc more easily?
I probably won't. Each new release on Instagram still has a splash page, but it only has the page number and the arc title.
I just direct new readers to Tapas via a link in the description if they want to read the old chapters. Honestly since I dropped the Pixel-Art style, it's been so much easier on my workflow. (I use CSP now. The text tool is pretty nice.)
Just gotta hope that my pages clearly weave into each other, I guess. The best way is to have a good enough buffer to post 2-3 pages at once in a big update, but that isn't feasible for me and I couldn't make more than that while on break, so it'd leave me in a rush to finish pages again.
Right now it's trying to get people to read it. I'm new to the site and therefore it's sort of hard learning all the things I need to do to get people interested.
HAVING TO DRAW EVERYTHING, BY MYSELF, ALONE.
Yeah. Time consuming.
No software, no programs, just me and my pencil.
For me I would probably say writers block. Although I obviously still have it when I'm writing a regular novel, I feel even more pressed with a webnovel. With a novel or work that I'm not publishing until its completed, if I have writers block I can easily just take some time off to edit previous chapters, do research, or write ahead. However, with an on-going webnovel, having writers block for too long can mean loss of fanbase, drastic change in writing style suddenly (which can be good and bad depending on how it's done), and sloopy, fast-pased writing that doesn't immerse the reader.