Why did fibers get added to php core over something more fleshed out like swoole?

I find it puzzling that the PHP internals have chosen to delegate this specific functionality to userspace implementation. Fibers, in my view, seem somewhat limited without the addition of a third-party library or, at the very least, the necessity to implement an event loop in userland. This raises questions, as it effectively obliges users to rely on third-party libraries to handle a fundamental feature rather than incorporating it into the core of PHP. Moreover, I'm curious about why PHPDBG doesn't implement the Language Server Protocol (LSP). Could it be due to its reliance on Xdebug? I came across this discussion on https://externals.io/message/78456, which makes me wonder about the decision-making process within PHP internals. It sometimes seems as though certain choices may not align with the best interests of the PHP community. I would appreciate it if you could provide insights into why this might not be the case. Lanre