They changed to a zip of JSON files, I believe the main reason was likely hackability – one of the main advantages Sketch has in the design ecosystem is it's pl

They changed to a zip of JSON files, I believe the main reason was likely hackability – one of the main advantages Sketch has in the design ecosystem is it's plugin architecture and the array of tools that exist around it. If you make your file format easy to work with then it only widens this moat.