For some kinds of data processing having your files in a local folder is a prereq. Every day I have my Obsidian vault open in Zed, and I interact with files via the tool-calling agent panel and via terminal.
I haven't tried Notion AI, maybe it's great. But I can't imagine going back to a world where all my knowledge lives in Notion's house. Notion CEO Ivan Zhao recently said: "If you think about applications, each application is kind of like a mini-prison of computing". (https://www.theverge.com/decoder-podcast-with-nilay-patel/75...) I think he's right. I don't want to be in Notion's prison even if it's big and nice.