I like this tech "fights" (evolutions). Even if bun will not overtake node, it will make node better. We see this many times with other projects (js/coffeescript/typescript/..., php/HHVM/HPHPc, webpack/vite/...)
Can't really find what the main benefits of io.js are though...
Why wouldn't bun, if it keeps its performance promises on its way to 100% node compatibility? I am intently keeping tabs on bun's progress because a better-engineered, faster, and leaner node-compatible runtime means $$ saved in server costs.
Besides, from the effort going into bun, it looks like the node community has its work cut out.