What's stopping people from working on another project? We have Ladybird [1], but it's still a work in progress. There are also LibreWolf, Icecat and other fork

What's stopping people from working on another project? We have Ladybird [1], but it's still a work in progress. There are also LibreWolf, Icecat and other forks of Mozilla Firefox. [1]: https://ladybird.org/ https://ladybird.org/