All the websites look the same but it's mostly because all the frameworks are the same. I'm thinking mainly of Bootstrap and Zurb Foundation. They share a lot of the same principles such as the 12-column grid, general typographic dimensions, button styles, etc. Granted, a lot of that stuff is for good reasons. In point of actual fact, I've studied their final CSS products and they share quite many implementation details.
There's also that "rule of threes" which almost every client likes.
Also, most of the new fonts are derivative. Amazon Ember looks like a bland mashup of Calibri and ITC Officina, like the latter of which a lot of other fonts look, and the former of which is bland as heck. Poppins looks like ITC Avant Garde Gothic. TheSansMono kind of looks like Consolas. There are a truckload of direct modifications of DejaVu Sans Mono/Bitstream Vera Sans Mono. Bitstream eVera Sans is a fugly bizarro version of Verdana/Tahoma.
There's also that "rule of threes" which almost every client likes.
Also, most of the new fonts are derivative. Amazon Ember looks like a bland mashup of Calibri and ITC Officina, like the latter of which a lot of other fonts look, and the former of which is bland as heck. Poppins looks like ITC Avant Garde Gothic. TheSansMono kind of looks like Consolas. There are a truckload of direct modifications of DejaVu Sans Mono/Bitstream Vera Sans Mono. Bitstream eVera Sans is a fugly bizarro version of Verdana/Tahoma.