It was the first version to treat the cloud not as a backup, but as a primary workspace. It was the first version to run natively on Apple Silicon, guaranteeing its relevance for the next decade. And it was the last version where the Pen tool was the undisputed king—before the rise of 3D, Intertwine, and generative AI features that would dominate version 26 and beyond.
Unlike the old CS days where you waited 18 months for a patch, the 2021 cycle was continuous. However, there were three major "dot" releases that defined the year: adobe illustrator 2021 version history