For example, LWN's most-recent report[0] on who contributed Linux kernel patches puts either three or four different companies above Red Hat, depending on if you're looking at changesets or lines changed.

Regardless, if leadership is theirs to lose, then they're doing a good job of it.

[0]: https://lwn.net/Articles/936113/

Kernel contributions are only one metric / piece of a distro, and these days a lot of the code churn is hardware if I’m not mistaken. It makes sense that Red Hat has slipped because the big changes are in new support for hardware.