Pfft, bookmarks.
I quit using those years ago when I discovered of the ~6000 or so neatly organised links, I only ever used about ten on a regular basis. If I need to bookmark something now, I just save the page. A lot of my old bookmarks are now invalid (site closed, domain changed, content removed et ...)
you should get a general idea of why i keep bookmarks.
I hate my phone. Stupid 320x240 resolution means your image is just a blurry mess.
Edit:
Yeah, makes sense now for someone who reads manga as it comes online. Still instead of a million bookmarks, why not just link to the site main page, and then find your manga from there. It'd be just as difficult as scrolling your massive bookmarks list and would save you time, unless you knew exactly how far down the list said manga was etc...
not exactly an ideal system no? using your way of taking notes its 100% impossible to remember at which page you stopped on said 1 of 1000 mangas you've read.
not every manga updates at the same time you know.
on the other hand if you were a librarian you'd know how to catalogue each bookmark to correspond to which folder(shelf) it should go, imagine how a librarian knows where a specific book is.
in contrast, having a big folder filled with your favorites would guarantee you finding your manga asap.
PS: its just management, i've had mine systematically arranged in which case i can find something easily.
in my case i've grouped mangas to each folder, so i just have to remember which specific folder holds one group, then search for the manga there.