It is not just logical argument that the internet hinders, it is ANY thought process that requires extended and deliberate thought. The ability to quickly jump to another website if one gets bored makes it difficult to do the deep diving necessary to really understand abstract concepts.
When I was obtaining my education, pre-internet, I only had physical libraries with a limited number of physical books on a topic. If I found a section of a book boring, I couldn't just hop to another one, there often wasn't one. As a result, I read books cover to cover and followed the author's train of thought from beginning to end.
Now I find myself only "skimming" or reading a portion of a wb page. Followng the tedious path of watching the author build and expound on abstract concepts is just simply too boring. I end up knowing a little about a lot instead of understanding a lot about a little.
You can't reallty learn without being bored some of the time and working through it. The internet makes it too easy to bail on boredom.