The packaging system is what originally brought me to debian and ubuntu; RPM caught up a while back, but apt was better for decades. Stability and easy access to good tooling is what I like about Ubuntu; how is Fedora better?

Fedora is a maintainers dream, in my (limited) opinion.

Things like mock and fedpkg make modifying upstream/bundling your own stuff up super easy. Then add in COPR (like PPAs) and it's a feedback-loop friendly setup

It's also a very "tidy" system to administer for the most part, although sometimes I get tripped up on the "sysconfig" stuff.

What does Fedora currently have that Ubuntu is missing?

Fedora just gets everything sooner. Newer kernels, gnome, packages. But it's still rock solid because of Red Hat/IBM.

Well, that's just bullshit.

You either get stuff sooner or get stuff more stable, you can't have 'rock solid' stuff sooner.

Depends what you mean by stable... In my experience, recent Fedora releases don't break. They also have the best laptop compatibility. But if 3rd party software (or your own software) targets specific libs, you need to keep up. Ubuntu is typically about one release cycle behind.

"the early bird get's the worm, but the second mouse get's the cheese."

Ubuntu feels to me like it’s been feature complete for about ten years and all we really get in the new versions are updated upstream apps and drivers, a stability crapshoot (sometimes better, sometimes worse), and an extension of support. Is Fedora doing anything different?

Fedora is where most of the innovations in Linux happen, because it's an upstream of CentOS Stream, which is an upstream of RHEL.

Manjaro! It gives you the best of Arch without the tinkerers overhead... I've used RHEL, Debian/Ubuntu, Slackware, et al, and Manjaro, for a laptop, is hands-down the best developer distro out there IMHO.