i mean, for a top-down approach i would probably also choose redhat because they seem to have structures for a streamlined b2b communication and commitment, but on the other hand i absolutely know nobody who uses it apart from the odd researcher and enterprise-it guys.
I believe it's the other way around: no other Linux distribution has a higher overlap with the target market of the Framework Laptop than Fedora.
Because unlike Ubuntu, Fedora Workstation has been specifically design for developers, hobbyists, and early adopters[1].
Personally, I only recommend and install Ubuntu for non-technical people, who don't need or care about always having the most modern OS features.
You either get stuff sooner or get stuff more stable, you can't have 'rock solid' stuff sooner.
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
Its where the new fun stuff goes first... not so new that it will bite you, but still new enough to be fun to play with. That seems perfectly in line with the marketing I see from framework.
Nice to hear that Framework plays well with Fedora, it will definitely be the next laptop I buy (if they ever start shipping to Norway).
but ime it is unpopular for personal use esp. in the enthusiast/dev/ops/hacker demographic that i consider to be a sizeable portion of the framework target market.
public opinion here also seems to suggest that my experience is less trustworthy than your feeling and tbh i mostly don't care wich flavor of unix is running my wm and browser.