(October 3, 2019) Did your YouTube home page recently switch to a horrible mode with large thumbnails that look like they're designed for old people with weak eyes? You probably didn't accidentally change a setting. Instead, YouTube (like any large web property) is always experimenting with user interface tweaks, and you probably got selected to be a test subject. In fact, you actually have been selected for an experiment, and you cannot "opt out" of that experiment according to a YouTube engineer. If you're like me, you hate this new design and are looking for an escape.