Hard disagree.
Pi has optimizations as well, and development is quite active.
We are literally months into this new frontier. Mainstream harnesses are not far off from a minimal + extensible open alternative.
You don’t have to build your own plugins, as you can simply install an existing plugin that does what the mainstream harnesses do. Folks are already making the same functionality, but with more control to the user.
If you are a builder, like many reading this thread, pi is the way to go. Pi already gives you the tools to leverage LLMs to assist with building plugins, if that’s the way you want to go.