Much like how people underestimate the time and effort it takes to build mature software from scratch, people also seem to under-estimate greatly the complexity

Much like how people underestimate the time and effort it takes to build mature software from scratch, people also seem to under-estimate greatly the complexity and effort involved in trying to make huge improvements to existing tools, both technical and political in nature. There's absolutely no chance that the vision the Bun folks had could be carried out in the Node.JS project in my opinion, the resulting attempt would have less impressive results and probably would leave everyone unsatisfied. One of the biggest benefits and most powerful features of open source is undoubtedly the fork, but just as important is knowing when not to do that, and that's definitely the case when the position you want to be is more different from any existing starting point than it is from scratch; I'd argue writing a 'fast' Pip-compatible package manager from first-principles is a perfect case for that. Re: politics. Note that sometimes forks and competitors are so successful, they make it possible for the upstream to "unblock" by virtue of convincing them to adjust their vision. For Node.JS, consider io.js and Yarn in particular.