I am using pi the same way everyone uses Codex and Claude, but pi makes it very simple to make folders to make the agent behave a certain way and that was easy for me to understand.
ChatGPT Desktop seems to intentionally hide what they are doing and where they are storing state, sessions, config, I never had any idea what is in context or what "archiving" even means. I got sick of OpenAI hiding how ChatGPT Desktop was working. I opened pi and the default behavior shows me how much context I am using, how much that costs and tells me where it stores my session data.
Suddenly it was all demystified and that is why I use pi. It has nothing to do with a functional gap, it was the joy a using a harness that was transparent about how it worked.