Perplexity is evolving from a Q&A tool into an agent operating system, following its historical launch of Computer and the Brain memory system, and now achieving cross-task persistence and team collaboration through Projects. The company is investing resources into shared files and self-learning memory, motivated by the goal of locking in long-term workflows rather than one-time queries, with funding shifting from search to productivity platforms. Similar cases can be seen in the AI integration of collaborative tools like Notion and Cursor, as well as early attempts at agents. Currently, AI is in a transition phase from conversation to continuous workspace, with the industry position evolving from assistants to multi-player operating systems. This is essentially a technological substitution: as temporary conversations are replaced by persistent projects, AI becomes a true work partner, leading capital to accelerate towards platforms with memory and collaboration capabilities. Persistent memory allows AI work to accumulate, a shared file system enables true collaboration, and project hubs replace temporary conversations.