Some people do things differently.

I know that when my time is constrained, I wouldn't want to spend a whole lot of time or labour waiting for downloads (especially on those file-hosting websites that tempt you with their premium services). Then you often have to unzip the compressed chapter, which takes more clicking.

If you think about it, it'd take about four clicks to get to a certain chapter of your liking (reader homepage, search, find title, click on chapter) and thereafter, you can use arrow keys to navigate through the pages.

When you're downloading chapters, it would probably be the same as above - except that unless it's a DDL, you'd probably have to go through a series of waiting, clicking and folder organization unless you've pre-programmed everything to do your bidding. Even so with DDL.

Really, in the time it takes you to download a chapter, unzip the compressed file and started reading them, I could be done reading 1.8 chapters.

Ultimately, consider the average and casual anime-manga fan. Streaming and readers are the method of choice among us. I'm lazy and I choose not to do this just for higher-quality pages. I skim through the content and get my entertainment's worth, but to each their own opinion.