Kind of surprised this is getting so much criticism. It’s a thought experiment, not a call for a fundamental change to all PC UX. My only real argument against the idea is that it’s framed as being “for efficiency”. If you want efficiency above all else you would just go full command line.
I believe it’s 1% for access to the “entire post-open ecosystem”, rather than 1% per project which would be unreasonable. So you could use one or thousands of projects under the Post-open banner, but still pay 1%.
It will take years to develop the post-open ecosystem to be something worth spending that much on.