The drawing usually takes a long time and it can vary from person to person. The author most likely wants to be able to have weekly updates so the chapters are shorter so they can do that. Or they could have other projects they are working on that also takes up time.
At first I really loved and enjoyed this manga but at this point I feel like the plot is repeating its self over and over and that there’s nothing new really going on. It got boring so I’m dropping it for now.
uploader-san, please keep uploading this because I really am liking this so far!