I agree, also the source code viewer (not sure what it's called) has regressed tremendously. A few years back it was simple, quite snappy and just worked. Now it has become slow and bloated and barely works for me on the desktop and the mobile version is full of rendering bugs rendering the whole thing rather useless. (Using firefox both on mobile and on the PC)
All they had to do, literally, was to do nothing but no, can't have that. MUST ADD BLOAT.
I wish it would remain as a basic viewer with syntax highlighting. If you want an edit/cursor mode you should have to click a button to enable it. At the moment, clicking on thepane places a cursor at that location which breaks using the arrow keys for scrolling the window -- if the cursor is off screen it will scroll to the cursor location not where the viewport is currently located.
A lot of these "improvements" fall into the following 3 categories:
1) More complexity around issue tracking
2) More complexity around permissions
3) IDE-ness and general visual-studioification of the web interface.
Since many of the issues make GitHub bloated and more difficult to use for general use cases, they _should_ be removed.