I think for most people it’s whatever you got used to first. I agree the hatred the GUIs get is overblown. I would always recommend people learn the command line but if you want to use a GUI, go for it, doesn’t affect me unless your commits are bad, in which case the CLI wouldn’t have helped anyway.
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.