I know I've been giving thoughts and feedback on the manuscript already, but I wanted to discuss here some stuff about the process of planning and making a piece of media because I think a lot of webcomic creators who haven't seen what it's like behind the scenes on bigger productions feel like they're the only ones struggling and that more experienced or pro creators have a smoother process, and it's actually the opposite.
In my day job, I work for a startup kids media company building a new IP around a series of books plus a limited run of online-exclusive episodes of animation with cartoon network. It has taken about TWO YEARS to get the book to the point where it's in the final tweaking stage to go to print, and the animated series to finally have the pilot in production, and details still keep being revised (and note, this book is not long, an adult can read it in about an hour). The manuscript has been jiggled around a lot, with loads of scenes being changed, removed or moved around, and it's been looked over by a bunch of editors, writers, tech experts, sensitivity readers etc. multiple times.
It is perfectly normal for the writing to take a lot of planning. I put in loads of planning work on Errant on both the story and the art. I'm on like.... draft 6 of the story, and the leadup to the comic I actually did a bunch of experiments on the style behind the scenes that have different inking and colouring styles and ways to use the colour palette and do shading etc (Also Urien's hair colour changed because that lilac really wasn't working):
One of the differences between making TV or movies and making animation,comics and other drawn media, is that you can't just roll the cameras while the actors are there, then prune it down because every drawing adds a lot of effort, so making finished, polished content only to cut it is a huge waste of resources. This means you can't necessarily save the movie in the edit like Marcia Lucas did to Star Wars after its disastrous preview screenings, but rather you have to edit before you draw for the best result.
I think spending years is overkill, but I've painted myself into corners with my webcomics in the past or seen my readers get confused about what happened or why, or complain about disappointing payoff to the setup or poor pacing, and if a few weeks of making and checking drafts can help me iron out those problems before I put all the effort into drawing it, I think that's preferable.