[lbotos]

You are mis-interpreting what they did. They literally took vim, and built a ui around it. No re-implementation. It's Vim with a more modern frontend stack. You can go look at the libvim source and see it for yourself.

The point of this is to bring Vim into more modern workflows, not but "vim compat" but literally... vim.

Source: had some pull requests into libvim a while back to remove a lot of the various legacy compat features that don't make sense for libvim.